Unit 731 and also known as the Kamo Detachment and Ishii Unit, was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army that engaged in lethal human experimentation and biological weapons ...

Experiments included, Vivisection, Biological warfare, Weapons testing on humans ("field testing" plague bombs by dropping them on Chinese cities to see whether they could start plague outbreaks), Frostbite testing, Syphilis, Rape and forced pregnancy.