Japanese human experimentation

Unit 731 (731 部隊, Nana-san-ichi butai^?) 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) and World War II. It was responsible for some of the most notorious war crimes carried out by Japanese personnel.
Unit 731 was the code name (tsūshōgō) of an Imperial Japanese Army unit officially known as the Epidemic Prevention and Water Purification Department of the Kwantung Army (関東軍防疫給水部本部, Kantougun Boueki Kyuusuibu Honbu). It was initially set up under the Kempeitai military police of the Empire of Japan to develop weapons of mass destruction for potential use against Chinese, and possibly Soviet forces.