The term “prisoner of war” dates as far back as 1660, recognizing an individual detained by an enemy power in the course of an armed conflict. These individuals are legitimately held to prevent them from rejoining the fight, but under modern international law cannot be punished for their legal actions during the war; instead, they are treated as protected individuals, unable to be conscripted, abused, or mistreated. During the Second World War, more than 10,000,000 soldiers were taken captive by the enemy at some point, including more than 5,000,000 Soviets under Nazi Germany. Although documentation is scarce, as with the end of the war Japanese Armed Forces systematically destroyed much of the limited available documentation related to their POW Camps, enough remains, in addition to survivor and witness accounts, to provide a horrific picture of life and captivity for Allied prisoners of war in the Pacific Theater.
Here are 20 Facts About Japanese Prisoner of War Camps During World War Two (Warning: The following article contains graphic imagery and content that might be upsetting to some individuals):
20. Almost 150,000 Allied soldiers were prisoners of war under the Japanese Empire, housed in more than 130 camps spread across East Asia
During the Second World War, the Japanese Imperial Armed Forces captured almost 140,00 Allied soldiers during the fighting in the Pacific and Southeast Asian Theaters. These prisoners of war, from dozens of nations, including but not limited to Great Britain, Australia, India, and the United States, were interred in camps throughout the enlarged territory of the Japanese Empire. In total, at least 130 such camps were opened in the course of the war to house Allied prisoners; some of these were prolonged, permanent facilities, whilst others were only in existence and use for brief periods of time.
These camps were spread across a vast area, deliberately so to prevent rescue missions and to provide material benefit to the local Japanese garrisons. Kept on the move, each time the Allies grew closer to liberating their captured comrades the Japanese relocated their prisoners. In addition to 36,000 Allied POWs transported to the Japanese Mainland, soldiers were imprisoned at locations in the Philippines, Singapore, China, Burma, Korea, and Hong Kong. Spanning a vast organizational complex, these individuals were eventually released after the surrender of the Japanese Empire on August 15, 1945.
19. Allied prisoners of war were forced to live on a deficient diet offering as little as 600 calories per day
The Empire of Japan, although not a signatory to the Second Geneva Convention of 1929, had agreed to its provisions prior to the start of the Second World War. Despite this, the Japanese refused to abide by the terms of the international accord, subjecting prisoners of war to truly horrific treatment. Although situations varied between camps, with Camp Commandants granted almost limitless discretion to determine rules, everyday conditions were uniformly bleak. Clothed in rags, Allied POWs were forced to subsist on a diet of sometimes as little as 600 calories per day, resulting in widespread malnourishment and critical levels of starvation.
During the “White Rice Period”, lasting from January to October 1942, Allied prisoners were granted a maximum of ten ounces of rice per day, in addition to two ounces of rancid pork and four ounces of fish monthly. This official figure was often larger than that actually provided, with theft by Japanese soldiers, themselves suffering from starvation towards the latter days of the war, commonplace within the camps. Red Cross parcels, containing necessary essentials, were accepted by the Japanese authorities, but rather than being redistributed among the prisoners were kept by the Japanese soldiers themselves.
18. More than 1 in 4 Allied POWs died during their residences in Japanese encampments during the Second World War
Due to the mass starvation, a general lack of available medical treatment, in addition to rampant abuse, Allied POWs faced bleak prospects for survival. According to the post-war Tokyo Tribunal, the death rate for Western prisoners was 27.1% across the Japanese internment program – a rate more than seven times higher than that of prisoners of war under either Nazi Germany or Fascist Italy. In fact, given that the rate for the 36,000 transported to Mainland Japan was just 10%, one can extrapolate that the rate in the predominance of many non-centralized camps was likely in excess of 40%.
Of particular note, in 1944 the Japanese War Ministry ordered all prison camp commandants to prepare for the “final disposition” of their guests. Instructing commandants to, in the event of an Allied invasion of their respective territory, liquidate the camps, the order stated that “it is the aim not to allow the escape of a single one, to annihilate them all, and not to leave any traces”. This order was carried out multiple times and, in preparation for an imminent invasion, Allied POWs held in Thailand were due to be executed on August 21, 1945. These prisoners had been forced to dig mass graves during the preceding weeks but were saved at the eleventh hour by the Japanese surrender on August 15.
17. Allied POWs were used as slave labor by the Japanese Empire, working 12 hour days under harsh conditions until they succumbed to starvation, illness, or maltreatment
In the course of their imprisonment, Allied POWs were forced to perform labor on behalf of their captors. Employed in mines, shipyards, fields, and factories, these harsh labors exacerbated the conditions of the already malnourished and ill prisoners. Those in Mukden Prison Camp, for example, worked for the Manchurian Tool Company under Mitsubishi, making tools and parts for military aircraft. The most unlucky, however, were sent to work on the Thai-Burma Railway, connecting Bangkok and Rangoon. Constructed between 1942 and 1943, the 415-kilometer railway resulted in the deaths of more than 100,000 laborers including, at least, 13,000 Allied prisoners of war.
Known colloquially as the “Death Railway“, more than 60,000 Allied POWs were forced to work from dawn until dusk to expedite the completion of the transportation system. Receiving only one day off in eleven, performing manual labor for an estimated 100 hours per week, these prisoners built bridges, laid track, and cut through mountains until they collapsed from the effort. These prisoners were housed in tiny barracks, measuring just 66 yards long, with 200 POWs to a house, providing each adult man only a two-foot wide space in which to sleep.
16. Unit 731, a covert research division of the Japanese Army, used Allied POWs for the purpose of human experimentation
Unit 731, part of the Imperial Japanese Army, served as a covert research and development organization during World War II. Established in 1935 under the Kempeitai, the Japanese military police, the unit was commandeered by General Shiro Ishii, with the Emperor’s permission, who transformed the secret group into the Epidemic Prevention and Water Purification Department of the Kwantung Army by 1940. Based in the Pingfang district of Harbin, located in Northeast China, it is estimated that in excess of 10,000 people were forcibly subjected to illegal experimentation, resulting in more than 3,000 deaths and with the Kempeitai procuring at least 600 victims per year for the clandestine research from POW Camps.
Despite the horrific nature of their crimes against both civilians and Allied POWs, many of the members of Unit 731 were granted immunity by the United States in the aftermath of the Second World War. Protected from war tribunals and almost certain execution for their criminal actions, the U.S. instead employed these individuals to enable them to contribute to America’s own biological warfare programs. In fact, the U.S. went so far as to dismiss and denigrate veterans who made accusations concerning members of Unit 731, branding their claims communist propaganda.
15. After invading the small Pacific island of Nauru in 1942, the Japanese imprisoned, enslaved, and killed much of the native population of the Australian protectorate
In the course of World War II, the small island of Nauru, strategically positioned in the Pacific Ocean, was occupied by the Japanese Empire. Invaded on August 26, 1942, the tiny island stood no chance against their industrialized military might and quickly fell. Despite earlier evacuations of essential personnel, five Australians, including the island’s administrator Lieutenant Colonel F.R. Chalmers, remained behind on the island to assist the local population. These individuals were initially imprisoned as POWs, before being later executed by the Japanese prior to liberation. In May 1946, Lieutenant Hiromi Nakayama would be sentenced to death for their unlawful killings.
The local population, themselves prisoners of war en masse as residents of an Australian protectorate, were treated equally poorly. Historically serving as a leper colony, in at least one recorded instance 39 afflicted persons were rounded up by the Japanese, loaded onto a boat, and subsequently sunk at sea as a method of execution. In 1943, 1,200 native Nauruans, representing almost 70% of the local population, were forcibly deported to the Chuuk Islands to serve as manual laborers. Less than two-thirds, just 737, would survive their captivity and return to the liberated island at the end of the war.
14. In the course of their experiments upon POWs, Unit 731 amputated the limbs of prisoners without anesthetic to study the effects of blood loss and improve battlefield medicine for Japanese soldiers
Like their Axis allies, the Nazis, the Japanese Empire was not averse to using incarcerated prisoners for the purposes of medical and military research. Among the subjects of interest to members of Unit 731, the secretive research group, was the improved survivability of Japanese soldiers on and off the battlefield. Seeking to understand the limits of human physical endurance, in particular the effects of major blood loss, Unit 731 engaged in the barbaric practice of non-consensual human testing. These individuals were typically not anesthetized and aware the entire time, with the pain suffered an integral part of the brutal experiments themselves.
One repeated form of this experiment was unnecessary medical amputation of certain limbs to study the consequences of battlefield medicine. Arms and legs would be removed, with patients observed to determine how long it might take for them to succumb, for wounds to attract infection or the tolerance of the body to increasingly large dismemberments. On other occasions, it has been recorded that limbs were surgically altered purely out of curiosity. These appendages would be reattached to the wrong parts of the body, or frozen until just the head and torso of the still-living prisoner remained.
13. During the Selarang Barracks Incident, more than 15,000 Allied POWs were denied basic sanitation, food, or water, in an attempt to deter them from seeking to escape from their captivity
After the British surrender of Singapore on February 15, 1942, captured Allied POWs were interned in the crowded Changi Prison and surrounding Selarang Barracks facility. After the unsuccessful escape of four Australians, all Allied POWs were ordered to sign a “No Escape Pledge” promising “on my honor that I will not, under any circumstances, attempt to escape”. All but three refused to sign the covenant, believing it was their duty to attempt escape and that under the Geneva Convention it was a protected right. Enraged, General Fukuye commanded all but the three who had conceded to be convened at the parade ground of Selarang Barracks.
Built to house 800 men, almost 17,000 POWs were packed into an area measuring 128 by 210 meters. For two days, these soldiers were denied access to toilets and permitted only a single quart of water per day. On the third day, with no sign of breaking his prisoners, Fukuye ordered the executions of the recaptured four escapees. Failing still to break the POWs, the lack of sanitation eventually took its toll, with fatal cases of dysentery spreading. On September 5, General Holmes ordered his fellow prisoners to sign “under duress” to spare any further loss of life. Although complying, most did so under false names, with hundreds using “Ned Kelly“: an Australian folk hero.
12. In addition to forced amputations, Allied POWs were subjected to vivisection and the removal, partial or complete, of major organs for scientific study
Whilst Western soldiers were treated inexcusably poorly, especially so by Unit 731, some of the worst horrors were reserved for Chinese POWs due to the racialist views of China by Imperial Japan. In the course of their experiments, Unit 731 routinely conducted vivisection – the performance of surgery on a living person for the purposes of study – on prisoners. Thousands of men, women, and children housed in POW Camps were subjected to these procedures, often resulting in the deaths of those unwillingly operated upon. These test subjects were infected, deliberately or otherwise, with serious diseases, whereafter their organs were removed to observe the effects of said disease on the human body.
One noteworthy instance involved the surgical removal of a prisoner’s stomach, after which their esophagus and small intestine were connected. Other unfortunate POWs had parts of their brains, lungs, and livers removed, to study the capacity of the human body to endure significant losses. It has been suggested by Imperial Army surgeon Ken Yuasa that the practice of vivisection on captured Chinese was not confined to Unit 731, but instead was widespread within the Imperial Japanese Armed Forces with more than 1,000 individuals performing said surgeries. This has yet to be definitively corroborated, but evidence exists to support this gruesome interpretation.
11. During the Nanjing Massacre, more than 200,000 surrendering Chinese were murdered by the Japanese, including thousands of POWs in brutal fashion
On December 13, 1937, the Japanese captured Nanjing, then-capital of the Republic of China. After disarming the surrendering population, approximately 200,000 Chinese prisoners were murdered by the occupying Japanese over a period of brutality lasting six weeks. As part of the “Rape of Nanjing“, Chinese soldiers were refused the quarter afforded to them under international law as prisoners of war. Stemming from “Riku Shi Mitsu No.198” – a directive issued on August 5 ordering Imperial Forces to no longer adhere to the restrictive term “prisoner of war” – the Japanese arrested and detained thousands of young men.
Transported to the Yangtze River, these POWs were murdered in what is believed to be the largest single massacre of Chinese soldiers. Taking more than an hour to shoot and bayonet the bound prisoners, the bodies of those killed in the “Straw String Gorge Massacre” were dumped into the river. A further 1,300 were taken to the Taiping Gate, where they were blown up with landmines, killed by bayonet, or coated in petrol and set alight. American correspondent F. Tillman Durdin reported that the streets were filled with the dead, whilst missionary Ralph L. Phillips testified after the war that he was “forced to watch while the Japs disemboweled a Chinese soldier” and “roasted his heart and liver and ate them”.
10. Female prisoners of war were raped, deliberately infected with syphilis, and forcibly impregnated for the purpose of scientific research by the Japanese
Although male prisoners of war under the Japanese Empire endured intolerable and sustained abuse, female prisoners equally suffered. In addition to being used alongside men for forced labor, women serving as POWs under the Japanese were routinely the victims of sexual assault. In the reflections of one former prison camp guard, on one such occasion “there was still time to kill. So he and another member took the keys to the cells and opened one that housed a Chinese woman. One of the unit members raped her”. In addition to the everyday rape of their bodies, unfortunate female prisoners became the subjects of experimentation by Unit 731.
Seeking to explore the vertical transmission of diseases, especially syphilis, from mother to child, POWs were forcibly infected and impregnated. According to the testimony of a guard, “the researchers started forcing the prisoners into sexual acts with each other…A male and female, one infected with syphilis, would be brought together in a cell and forced into sex with each other”. After this process, the women were vivisected at various stages to observe the progression of the disease. Whilst it is known that “a large number of babies were born in captivity”, with recorded accounts of children at the facility, there are no records of children surviving Unit 731 suggesting these infants were put to death once they had served their scientific purposes.
9. In blatant defiance of the Geneva Convention, Allied prisoners of war under Japanese control were routinely tortured for information
During World War II, the Japanese regularly tortured those they captured. As Uno Shintaro, an officer stationed in China, later recounted: “torture was an unavoidable necessity. Murdering and burying them follows naturally. You do it so you won’t be found out”. Among the methods used by the Japanese was the “water cure”, wherein a person is forced to drink excessive quantities of water. Summarized by the International Military Tribunal for the Far East, “the victim was bound or otherwise secured in a prone position. Water was forced through his mouth and nostrils into his lungs and stomach until he lost consciousness. Pressure was then applied, sometimes by jumping upon his abdomen to force the water out. The usual practice was to revive the victim and successively repeat the process”.
Another method employed by the Japanese was the use of “bamboo torture“. Tying prisoners over a bed of sharpened bamboo shoots, capable of growing a couple of inches per day, the plant penetrates and impales the individual in a matter of days. Placed in a position of agonizing pain, the prisoner would suffer as the plant worked its way through his body, eventually killing him unless he relented and provided information. Whilst some have claimed the use of bamboo by the Japanese is apocryphal and ineffective, a 2008 investigation by Mythbusters determined the shoots are capable of stabbing through several inches of ballistic gelatin in less than three days.
8. As part of a range of environmental conditional testing, prisoners of war had limbs deliberately exposed to frostbite and were sealed in high-pressure chambers to observe the limitations of the human body
Among the countless horrific experiments performed on Allied prisoners, Dr. Yoshimura Hisato of Unit 731 became fascinated in exploring the effects of frostbite upon the human body. Freezing certain body parts, these appendages “when struck with a short stick, emitted a sound resembling that which a board gives when it is struck”. Thereafter, ice was chipped away to determine the scale of the tissue damage and lasting physiological consequences of severe freezing.
In one particularly gruesome recollection, a former guard recounted how, in the course of raping female Chinese prisoners, his group had encountered a woman who “had been used in a frostbite experiment. She had several fingers missing and her bones were black, with gangrene set in. He was about to rape her anyway, then he saw that her sex organ was festering, with pus oozing to the surface. He gave up the idea”. Not isolated to only the extremes of cold, Japanese researchers sought to understand the effects of a wide range of environmental conditions including pressure – placing individuals in high-pressure chambers until their eyeballs popped out – and radiation – caused by exposing prisoners to lethal x-rays.
7. In violation of international law, Allied airmen were refused the title of “prisoner of war”, instead of being treated as criminals and frequently executed after show trials
According to the Hague Convention of 1907, of which Japan was a signatory, any military personnel captured in war could not be punished for being lawful enemy combatants. On August 13, 1942, Imperial Japan enacted the Enemy Airmen’s Act, passed in response to the Doolittle Raid, stipulating that any Allied pilots who bombed non-military targets in the Pacific Theater would be treated as criminal and not a prisoner of war if caught. Eight airmen from the Doolittle Raid were brought before a Shanghai court, where they were refused the opportunity to mount any legal defense to their charges and three were sentenced to death by firing squad.
This act marked the beginnings of the recurrent prosecution and execution of Allied POWs under the illusion of criminal justice. In total, an estimated 132 Allied airmen shot down during the 1944-1945 bombing campaign were convicted and executed by Japanese show trials. A further 94 died whilst in custody, in addition to an unknown figure as a result of tolerated public lynchings. Most egregiously, 15 captured Allied airmen were hurriedly beheaded on August 15, 1945, at Fukuoka, shortly after the Japanese Government announced its intention to surrender to the Allies.
6. Facing Allied liberation, almost 150 POWs held at Puerto Princesa in the Philippines were massacred by the Japanese rather than be allowed to be free
In response to advancing Allied forces in the Philippines, on December 14, 1944, soldiers of the Japanese Fourteenth Area Army, under the command of General Tomoyuki Yamashita, initiated the aforementioned liquidation order of the War Ministry. In an attempt to prevent the approximately 150 POWs held at Puerto Princesa, located in the Philippine province of Palawan, from being rescued by their comrades, these prisoners were herded by the Japanese into shelter trenches under the pretext of an incoming air raid. Once assembled, the POWs were doused in gasoline and set on fire; those who attempted to escape the flames were shot by machine gun.
In total, just 11 of the 150 prisoners survived, scaling a cliff along the side of the trench. The testimony of one of these survivors, Private First Class Eugene Nielsen, sparked outrage and a mass operation by the Allies to retrieve as many of their captured soldiers before they could be similarly executed by the Japanese. On January 30, the U.S. launched a raid on Cabanatuan, on February 3 at Santo Tomas Internment Camp, on February 4 at Bilibid Prison, and on February 23 at Los Baños. Although 16 Japanese soldiers were sentenced to death in 1948 for their role in the Palawan Massacre, they were released as part of an amnesty before execution.
5. Human experimentation on Allied prisoners of war extended to the fatal injection of animal blood as part of the search for medically viable substitutes for front-line transfusions
As noted, much of the human experimentation conducted by the Empire of Japan on Allied prisoners of war was done in the name of preservation. Seeking to find more effective methods to protect and repair their own soldiers the Japanese were prepared to sacrifice those they captured in the course of the Second World War, individuals that were culturally viewed as innately inferior to the superior “Yamato” race. Consequently, much of the research that was conducted by Japanese scientists, notably those employed by Unit 731, focused on the conditional limits of survival, medicinal practices, and physiological endurance.
One such noteworthy medical experiment included the injection of animal blood into humans as a test case for blood transfusions. Horse blood was administered to Allied POWs to explore the possibility of using non-human blood as a substitute for increasingly scarce supplies of human blood on the front lines. Unsurprisingly, the procedure was a failure, resulting in the deaths of the prisoners in the trial. Similarly, prisoners were forcibly injected with concoctions including seawater; these tests, likewise, proved fatal.
4. Towards the end of the war, with supplies running low, the Japanese resorted to the murder and cannibalism of Allied POWs
Committed in response to Allied attacks on Japanese supply lines, resulting in widespread starvation among Japanese soldiers, according to historian Yuki Tanaka “cannibalism was often a systematic activity conducted by whole squads and under the command of officers”. Many of these acts were the product of murder to acquire the meat, with Indian POW Changdi Ram testifying that on November 12, 1944, “the Kempeitai beheaded [an Allied] pilot. I saw this from behind a tree and watched some of the Japanese cut flesh from his arms, legs, hips, buttocks and carry it off to their quarters … They cut it [into] small pieces and fried it”.
Similar instances were systematically corroborated by other Allied prisoners, with Hatam Ali recounting that in New Guinea “the Japanese started selecting prisoners and every day one prisoner was taken out and killed and eaten by the soldiers. I personally saw this happen and about 100 prisoners were eaten at this place by the Japanese. The remainder of us were taken to another spot 50 miles [80 km] away where 10 prisoners died of sickness. At this place, the Japanese again started selecting prisoners to eat. Those selected were taken to a hut where their flesh was cut from their bodies while they were alive and they were thrown into a ditch where they later died.”
3. With diseases the leading cause of soldier fatality, Japanese researchers began testing vaccines on deliberately infected prisoners to determine their effects on humans
In the course of the Sino-Japanese War (1937-1945), the Japanese discovered a horrid truth about modern warfare: that the overwhelming majority, in fact as high as 89 percent, of battlefield fatalities were caused not by the fighting but from diseases. In an attempt to better understand these illnesses, in addition to synthesizing vaccinations and cures, researchers at Unit 731 deliberately infected POWs. Forming one of the eight core divisions of Unit 731, this division, numbering approximately 300 researchers, focused on bacteriological diseases, notably cholera, anthrax, typhoid, tuberculosis, and the plague.
Some of the findings of researchers from Unit 731 were published contemporaneously in peer-reviewed journals, disguising that the research had been conducted on non-human primates. Subjects, for example, Chinese prisoners, were referred to as “Manchurian monkeys” or “long-tailed monkeys”, reflecting the sub-human nature in which POWs were viewed by the Japanese Empire. Their corpses were subsequently incinerated to eliminate evidence of wrongdoing by the Japanese military. The consequences of these methods can be seen in Indonesia on August 6, 1944, where an estimated 900 men were injected with an experimental vaccine. This vaccine, designed to combat tetanus, instead induced a fatal reaction to those administered; in total, it is believed nearly 1,000 people were killed by this failed test.
2. The Japanese repeatedly forced Allied prisoners of war to embark on prolonged marches with little to no provisions, resulting in the deaths of thousands
In the aftermath of the Battle of Bataan and the surrender of Allied forces in the Philippines, captured prisoners of war needed to be relocated to be housed and exploited for labor. Beginning on April 2, 1942, between 60,000 to 80,000 POWs were marched from Mariveles to San Fernando, loaded onto trains to Campas Train Station, and marched from there to Camp O’Donnell – a total of approximately 70 miles by foot. During this forced march, in which POWs were provided little to no food or water, and those that requested provisions were shot by the Japanese, an estimated 18,000 Filipino prisoners and 650 Americans died.
Such marches were not uncommon for Allied prisoners during the Second World War, with the Sandakan Death March similarly occurring in 1945. Facing Allied invasion, the Japanese sought to move POWs into the mountains to prevent easy liberation. From January to March, a total of 470 POWs were marched into the mountains; with limited rations, and suffering from serious illnesses, just 6 were still alive by June 26. The second round of prisoners was marched from May, whereupon just 183 out of 536 POWs survived the journey. A final round, starting in June, comprised of 75 prisoners, was marched into the mountains, with not a single one lasting more than 50 kilometers of the journey.
1. Allied POWs were used as human subjects of weapons tests, both for conventional armaments and for biological weaponry
As with all weaponry, tests must be conducted to determine their efficacy and during World War II the Japanese military opted for using Allied prisoners as human guinea pigs for these new technologies. POWs were tied to stakes whilst jars of cyanide were thrown at them, recorded in November 1944 in the Kai Islands, set alight with flamethrowers, targeted with tank cannons, and to test the range of grenade explosions. Most horrifically, prisoners were consciously exposed to diseases, such as typhoid and plague, and monitored to determine the effects of prolonged exposure and observe the deterioration of the afflicted.
The use of biological weapons by the Japanese was confirmed, with Chinese and South Asian targets bombarded with plague-infected fleas dispersed over populations by planes. An estimated 580,000 people were killed by the Imperial Japanese Army’s deliberate spread of plagues during the Second World War. In fact, during the concluding months of the war, Japan planned to unleashed biological weapons upon the mainland United States. Operation Cherry Blossoms at Night, using diseases concocted by Unit 731 using prisoner research, was intended to release plagues against the civilian inhabitants of San Diego, California, starting on September 22, 1945.