The Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, has released two newly compiled sets of historical evidence marking the 81st anniversary of Japan's unconditional surrender in World War II.

The materials, including personnel records and oral testimonies from the Hailar branch of Unit 731, provide further evidence of its role in Japan's biological warfare system and shed new light on its recruitment, training and human experimentation activities.