China's Foreign Ministry on Friday urged Japan to deeply reflect on its wartime crimes and make a clean break with militarism, saying history must not be revised, after reports that a museum in Nagasaki planned to alter references to the Nanjing Massacre.

According to media reports, Japan's Nagasaki atomic bomb museum is updating its displays and plans to replace references to the "Nanjing Massacre" with the term "Nanjing Incident," described as an event in which many civilians and prisoners of war were killed.

"The Nanjing Massacre was a brutal crime committed by Japanese militarism. The evidence is irrefutable and cannot be altered," Chinese Foreign Ministry spokesperson Mao Ning told a daily press briefing.

Mao said the Tokyo Trials had clearly characterized the atrocities committed by Japanese troops in Nanjing as a "massacre," not an "incident," and that the judgments of the International Military Tribunal for the Far East established the crimes through survivor testimony, records kept by foreign witnesses and Japanese military archives.

Iwane Matsui, one of the principal perpetrators of the Nanjing Massacre, was sentenced to death by hanging as a Class-A war criminal, she noted.

"History does not allow revisionism," Mao said, adding that many Japanese atomic bomb survivors, civic groups in Nagasaki and other prominent figures had called for a correct and complete reflection of the history of Japanese militarism as an aggressor.

"We urge Japan to deeply reflect on its wartime crimes and completely sever itself from militarism," Mao said.