(ECNS) -- New evidence detailing Japan's use of biological weapons during World War II was unveiled Friday at a memorial hall in Harbin City, Heilongjiang Province, shedding further light on the crimes committed by the notorious Unit 731.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards, and eight letters, offering detailed evidence of Japanese germ-warfare.

Jin Chengmin, curator of the Exhibition Hall of Evidence of Crime Committed by Unit 731 of the Japanese Imperial Army, said that the latest evidence falls under three main categories.

The first category includes evidence and historical materials from official Japanese institutions. These archival documents list the names, birth dates, places of origin, and enlistment details of Unit 731 members, serving as core materials for studying Japan's germ-warfare operations.

The second category comprises the oral testimonies of Unit 731 members, obtained during a 2018 trip to Japan. These testimonies reveal some cruel details of Japan's biological warfare, such as a soldier's experiences while visiting a dissection room.

The third category features photographs and information about Japanese medical students, highlighting the close ties between the military and medical institutions during that period.

"History brooks no doubt, and the truth must be remembered," Jin said. He added that the newly released evidence further reveals the structure of Japan's germ-warfare system and once again proves it was a premeditated, organized state crime carried out from the top down.

Friday marks the 80th anniversary of Japan's announcement of its unconditional surrender, as well as the 40th anniversary of the establishment of the Exhibition Hall of Evidence of Crime Committed by Unit 731 of the Japanese Imperial Army.

(By Zhang Dongfang)