Unit 731 (Japanese: 731部隊 Hepburn: Nana-san-ichi Butai), also referred to as Detachment 731, the 731 Regiment, Manshu Detachment 731, The Kamo Detachment,[3]:198 Ishii Unit,[5] Ishii Detachment[5] or the Ishii Company, was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army that undertook lethal human experimentation during the Second Sino-Japanese War (1937–1945) of World War II. It was responsible for some of the most notorious war crimes carried out by Imperial Japan. Unit 731 was based at the Pingfang district of Harbin, the largest city in the Japanese puppet state of Manchukuo (now Northeast China), and had active branch offices throughout China and Southeast Asia.
