Shiro Ishii, commander of Unit 731 More than ten thousand people, from which around 600 every year were provided by the Kempeitai, were subjects of the experimentation conducted by Unit 731. More than 95 percent of the victims who died in the camp were Chinese and Korean, including both civilian and military. The remaining 5 percent were South East Asians and Pacific Islanders, at the time colonies of the Empire of Japan, and a small number of the prisoners of war from the Allies of World War II. According to the 2002 International Symposium on the Crimes of Bacteriological Warfare, the number of people killed by the Imperial Japanese Army germ warfare and human experiments is around 580,000. According to other sources, the use of biological weapons researched in Unit 731's bioweapons and chemical weapons programs resulted in possibly as many as 200,000 deaths of military personnel and civilians in China. Unit 731 was the headquarters of many subsidiary units used by the Japanese to research biological warfare; other units included Unit 516 (Qiqihar), Unit 543 (Hailar), Unit 773 (Songo unit), Unit 100 (Changchun), Unit Ei 1644 (Nanjing), Unit 1855 (Beijing), Unit 8604 (Guangzhou), Unit 200 (Manchuria) and Unit 9420 (Singapore). Many of the scientists involved in Unit 731 went on to prominent careers in post-war politics, academia, business, and medicine. Some were arrested by Soviet forces and tried at the Khabarovsk War Crime Trials; others surrendered to the American Forces. On 6 May 1947, Douglas MacArthur, as Supreme Commander of the Allied Forces, wrote to Washington that "additional data, possibly some statements from Ishii probably can be obtained by informing Japanese involved that information will be retained in intelligence channels and will not be employed as 'War Crimes' evidence." The deal was concluded in 1948. Because of their brutality, Unit 731's actions have now been declared by the United Nations to have been crimes against humanity. Weapons testing: ▪ Human targets were used to test grenades positioned at various distances and in different positions. ▪ Flame throwers were tested on humans. ▪ Humans were tied to stakes and used as targets to test germ-releasing bombs, chemical weapons and explosive bombs. Germ warfare attacks: ▪ Prisoners were injected with inoculations of disease, disguised as vaccinations, to study their effects. ▪ To study the effects of untreated venereal diseases, male and female prisoners were deliberately infected with syphilis and gonorrhea, then studied. ▪ Prisoners were infested with fleas in order to acquire large quantities of disease-carrying fleas for the purposes of studying the viability of germ warfare. ▪ Plague fleas, infected clothing, and infected supplies encased in bombs were dropped on various targets. The resulting cholera, anthrax, and plague were estimated to have killed around 400,000 Chinese civilians. ▪ Tularemia was tested on Chinese civilians. ▪ Unit 731 and its affiliated units (Unit 1644, Unit 100, et cetera) were actively involved not only in research and development, but also in experimental deployment of epidemic-creating biowarfare weapons in assaults against the Chinese populace (both civilian and military) throughout World War II. Plague-infested fleas, bred in the laboratories of Unit 731 and Unit 1644, were spread by low-flying airplanes upon Chinese cities, coastal Ningbo in 1940, and Changde, Hunan Province, in 1941. This military aerial spraying killed thousands of people with bubonic plague epidemics. Other experiments: Prisoners were subjected to other experiments such as: ▪ being hung upside down to see how long it would take for them to choke to death. ▪ having air injected into their arteries to determine the time until the onset of embolism. ▪ having horse urine injected into their kidneys. ▪ being deprived of food and water to determine the length of time until death. ▪ being placed into high-pressure chambers until death. ▪ being exposed to extreme temperatures and developing frostbite to determine how long humans could survive with such an affliction, and to determine the effects of rotting and gangrene on human flesh. ▪ having experiments performed upon prisoners to determine the relationship between temperature, burns, and human survival. ▪ being placed into centrifuges and spun until dead. ▪ having animal blood injected and the effects studied. ▪ being exposed to lethal doses of x-ray radiation. ▪ having various chemical weapons tested on prisoners inside gas chambers. ▪ being injected with sea water to determine if it could be a substitute for saline. ▪ being buried alive. (Victims included infants.) Biological warfare: Japanese scientists performed tests on prisoners with plague, cholera, smallpox, botulism and other diseases. This research led to the development of the defoliation bacilli bomb and the flea bomb used to spread the bubonic plague. Some of these bombs were designed with ceramic (porcelain) shells, an idea proposed by Ishii in 1938. These bombs enabled Japanese soldiers to launch biological attacks, infecting agriculture, reservoirs, wells, and other areas with anthrax, plague-carrier fleas, typhoid, dysentery, cholera, and other deadly pathogens. During biological bomb experiments, scientists dressed in protective suits would examine the dying victims. Infected food supplies and clothing were dropped by airplane into areas of China not occupied by Japanese forces. In addition, poisoned food and candies were given out to unsuspecting victims and children, and the results examined.