In 1942 , the Japanese military began testing various chemical and biological agents as an alternate method to win the war . Human experiments were conducted on Chinese and Korean civilians ; Allied POWs were also subjected to experimentation . After the war , China ( PRC ) demanded data from these experiments in exchange for not raising the issue , while the U.S. granted immunity from prosecution to many of the scientists involved ( see Unit 731 ) in exchange for their weapons research
Unit 731
Unit 731
2005 anti-Japanese demonstrations