Japan’s Unit 731 was a top-secret biological and chemical warfare research base established in Northeast China in 1935 as the center of its biological warfare in China and Southeast Asia during WWII.
The unit was infamous for conducting brutal and often fatal experiments on living humans and developing biological weapons.
Historians believe that some 3,000 people died in the human experiments conducted by the unit, including Chinese civilians and captives from China, Russia, Korea, the U.S. and Europe.
Yet the Japanese government denied the existence of Unit 731 until 1998. Tokyo says it knows nothing about specific wrongdoing by the unit.