This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

An aerial drone photo shows the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army and the former site of the Unit 731 in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

Jin Shicheng, a researcher with the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army, puts the new evidence of Unit 731 in place at the hall in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

Jin Shicheng, a researcher with the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army, puts the new evidence of Unit 731 in place at the hall in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

The unveiling of new evidence of Unit 731 is held at the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

An aerial drone photo shows the former site of the Unit 731 in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

Jin Shicheng, a researcher with the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army, puts the new evidence of Unit 731 in place at the hall in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

An aerial drone photo shows the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 15, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

Jin Shicheng, a researcher with the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army, puts the new evidence of Unit 731 in place at the hall in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)

This photo shows the new evidence of Unit 731 unveiled by the Exhibition Hall of Evidences of Crime Committed by Unit 731 of the Japanese Imperial Army in Harbin, northeast China's Heilongjiang Province, Aug. 13, 2025.

New evidence of Unit 731 -- a Japanese germ-warfare unit that operated during World War II -- was unveiled on Friday in Harbin, the capital of northeast China's Heilongjiang Province.

The new evidence includes 3,010 pages of archive documents, 194 minutes of video footage, 312 photographs, 12 postcards and eight letters, exposing Japanese germ-warfare crimes in detail. (Xinhua/Wang Song)