A large number of files discovered by the Jilin provincial archives administration recently reveal the grim world of helplessness and suffering that Japanese troops unleashed on China through their large-scale human experimentation, which was carried out by the notorious Unit 731.

The 81-volume written and audio-video materials were prepared by Japanese troops from 1936 to May 1945 and left behind in China when they hastily withdrew from the country after the end of World War II, Xinhua News Agency has said.

Unit 731, based in Pingfang district of Harbin in Heilongjiang province, was led by the infamous Japanese microbiologist Shiro Ishii. It was a covert biological warfare research and development unit that undertook human experimentation during Japanese occupation of parts of China. The notorious Japanese unit was the most active in China, where it carried out biological, bacterial and chemical weapons' tests on civilians and prisoners of war, which included Russians and Koreans.

The newly discovered materials record such activities by Unit 731 in Changchun, Jilin province, and other places, and the transfer of experiment targets to the unit and some activities of Shiro Ishii, who was one of the leaders of Japan's bacterial warfare forces. These archival materials also record the "Special Transfer" of 372 people to Unit 731 for experimentation.

According to Gao Wei, in charge of a Jilin provincial archives administration research team on Japan's biological and bacterial warfare, the "Special Transfer" meant the transfer of some "valueless" prisoners of war to Unit 731 for biological and bacterial research on humans, mostly through vivisection. On Jan 1, 1938, the Japanese army stationed in Northeast China laid down a set of standards for the "Special Transfer" targets, that is, mainly people engaged in "espionage", and the national liberation and the communist movements.

"Through studies on Japan's 18 military legions distributed across occupied Chinese territories and the timing of the establishment of hundreds of departments related to bacterial experiments, we have found that Japanese troops set up a bacterial warfare unit in every Chinese territory they occupied," Gao says. This testifies that the establishment of Unit 731 and other forces for bacterial warfare was one of Japan's most important strategies for aggressive expansion in China.

According to records, 2.37 million Chinese people became the victims of 161 bacterial attacks that Unit 731 carried out in more than 20 provinces of China. The State Archives Administration data show that about 270,000 Chinese people died in barbaric bacterial attacks launched by the unit and other Japanese forces.