HARBIN, July 6 (Xinhua) -- Atrocities committed by the notorious Japanese Army Unit 731, a germ war unit once stationed in northeast China's Heilongjiang Province, was further revealed in newly found historical documents.
The 24 documents were collected in Japan and were written by major members of Unit 731, according to Yang Yanjun, associate researcher at the Unit 731 Research Center of Harbin Academy of Social Sciences.
Unit 731 was a biological and chemical warfare unit in the Japanese Army during WWII.
Yang said some of the surveys were conducted within the puppet Manchurian regime, covering the expansion of a bacterial research base and research on bacteria culture mediums, infections and bacteria attack methods.
Soldiers in the unit also took photographs and wrote papers on the region's wetlands, geology, mountains, and water resources to prepare for the germ warfare and provide reference for Japanese immigrants.
Other documents included materials collected by the army unit on epidemic prevention, geology, transport, and related polices and laws of the former Soviet Union.
The documents were produced between March 1937 and November 1939, Yang said.
The new evidence is significant in the study of Unit 731 as its shows the unit's range of activity and research content.
"The documents have revealed Japanese germ warfare systems and war crimes committed by Unit 731," Yang said.
Unit 731 was established in Harbin in 1935, during the Japanese army's occupation of northeast China.