Concealment of Experimentation
Unit 731 was formally known as the Epidemic Prevention and Water Purification Department of the Kwantung Army to Japan, and the bioweapons laboratories in Manchuria were disguised as lumber mills.
After the conclusion of World War II, Unit 731 scrambled to erase all traces of human experimentation in China.
Source: YouTube- New China TV
"[Other medical workers and I] were ordered to bury these complete and partial remains [of human victims] after Japan surrendered to the US in August, 1945."
- former nurse who worked at the Imperial Japanese Army Medical College in Shinjuku