In 1938 the biological warfare establishment Unit 731 had been set up outside Harbin in Manchukuo, under the auspices of the Kwantung Army. This huge complex, presided over by General Ishii Shir, eventually employed a core staff of 3,000 scientists and doctors from universities and medical schools in Japan, and a total of 20,000 personnel in the subsidiary establishments. They prepared weapons to spread black plague, typhoid, anthrax and cholera, and tested them on more than 3,000 Chinese prisoners.
