100 Squadron

The Unit 100 was a secret unit of the Imperial Japanese Army that focused on the development of biological weapons during World War II . It was operated by Kenpeitai , the military police of the Empire of Japan . It was located in Mokotan, Manchukuo , a town south of Changchun City and was masked as an “epidemic prevention and water supply unit.” 1


The main purpose of Squadron 100 was to conduct research on diseases that originated in animals. Since most armies still depended heavily on horses , the Imperial Japanese Army hoped to find ways to kill them and thereby weaken the military power of their enemies. In addition, they hoped to spread diseases through animal carriers. To this end, experiments were also carried out with humans, but few records or tests of human experimentation have been preserved. In practice, the 731 Squadron was the group in charge of developing biological weapons. Although it was smaller than the 731 Squadron, Squadron 100 was a great organization. A year, its productive capacity of bacteria was projected to reach one ton of Bacillus anthracis , 500 kg of Burkholderia mallei and 100 kg of red fungi; Nevertheless, never they reached their goal, due to the scarcity of equipment.

Sergeant Kazuo Mitomo described some of the experiments performed by Squadron 100:

“I put like a gram of heroin in one gacha and gave it to a Chinese civilian prisoner who ate it, about 20 minutes later lost consciousness and remained in that state until he died 15-16 hours later. Of heroin is fatal, but we were not interested if he died or lived. In some prisoners I experienced 5-6 times, watching the action of Korean corridors, bactal and castor bean . One of the prisoners of Russian nationality was so exhausted from the Experiments to such an extent that he could no longer experience it, and Matsui ordered me to kill him by injecting him with potassium cyanide. “After the injection, the man died immediately, and the bodies were buried in the squadron’s graveyard.”

Squad leader Yujiro Wakamatsu ordered Hirazakura to buy hundreds of cattle and graze them on the border with the Soviet Union northeast of Hailar, ready to be infected by aerial dispersal. They hoped that in the face of a Soviet invasion, infected cattle would mix with local herds, causing epidemics and destroying food supplies.


  1. Back to top↑ Harris, Sheldon H. (1994) Factories of Death: Japanese Biological Warfare, 1932-45, and the American Cover-Up . London: Routledge.