Visitors watch the displays in a museum about Japanese Army Unit 731 wartime atrocities in Harbin, capital of northeast China's Heilongjiang Province, Sept. 18, 2015. The Museum of Evidence of War Crimes by Japanese Army Unit 731 has seen a surge of visitors during summer time since it opened on Aug. 15. The museum receives about 9000 people per day and a total of 243,000 have visited so far. Notorious Japanese Unit 731 was a biological and chemical warfare research base established in 1935. At least 3,000 people died at the base between 1939 and 1945, mostly in experiments for the development of biological weapons. (Xinhua/Wang Kai)
