The Nanjing Massacre Memorial Hall in the Chinese city. Chinese historians claim Japanese troops killed more than 300,000 in a six-week rampage in 1937, but Japanese historians insist the number was lower. Photograph: STR/AFP/Getty Images The Nanjing Massacre Memorial Hall in the Chinese city. Chinese historians claim Japanese troops killed more than 300,000 in a six-week rampage in 1937, but Japa