The picture taken on July 1, 2014 shows the cover of Ironclad Evidence, newly published book revealing Japan's atrocities during World War II. [Photo by Liu Xiaozhuo/chinadaily.com.cn]

A collection of newly-deciphered evidence about Japan's invasion of China recorded by a Japanese monthly newspaper and confidential records of the Japanese military police during World War II were released on Tuesday in Changchun, capital city of Jilin province.

Archives reveal Japan's WWII atrocities

Entitled Ironclad Evidence, the book, detailing research about Japan's atrocities, was translated and collated by Jilin Provincial Archives and published by the Jilin Publishing Group.

The book draws together 450 reports selected from some 45,000 files written in Japanese. They were discovered by construction workers in the 1950s in the back yard of the former headquarters of the Japanese Kwantung Army in Changchun.

According to Mu Zhanyi, vice-director of the Jilin Provincial Archives, the documents, which Japan had never expected to be open to the pubic, record in detail Japan's invasion activities, battle plans and colonization strategies.

Included are detailed records of key incidents and sensitive topics in Japan's aggression towards China and the Pacific War, such as an activity record of bacteria experiment Unit 731; how the Japanese army forced Chinese, South Korea and Republic of Korea women to be sex slaves and Japanese working reports on the Nanjing Massacre in 1937.

"These archives are of great historical research value and show Japan's cruelty and ambition to conquer the world which provides more convincing and undeniable evidence to prove Japan's invasion and brutality to people in China and Southeast Asia," Mu said.