LOS ANGELES, Sept. 19 (Xinhua) -- "Evil Unbound," a Chinese-produced film depicting the atrocities committed by the notorious Japanese germ warfare Unit 731 during World War II, held its Los Angeles premiere Thursday. Unit 731, a top-secret biological and chemical warfare research base in Harbin, the capital of northeast China's Heilongjiang Province, served as the nerve center for Japanese biological warfare in China and Southeast Asia during WWII. Historical records indicate that from 1940 to 1945, Unit 731 used at least 3,000 people in human experiments, and more than 300,000 people in China were killed by Japan's biological weapons. After the premiere on Thursday, a moviegoer who identified himself as Richard told Xinhua that watching "Evil Unbound" was "very hard, very emotional, very difficult." "I hope a lot of people will come and watch this movie to get a better sense of that part of history."