Newly sorted archives in northeast China's Jilin Province have revealed the Japanese army's indiscriminate bombing of southwest China's Chongqing Municipality and other cities during its invasion 75 years ago.

The documents, released by the Jilin Provincial Archives on Wednesday, show the Japanese army ordered mass bombings in Chongqing for three consecutive days in the summer of 1939.

An archived Japanese monthly newspaper from September 1939 recorded in detail that eight children were killed, over 10,000 people injured, 30 households burnt down, and one fifth of the city was destroyed during the campaign.

Another such monthly newspaper from June 1939 recorded that Japanese bombers attacked a region inhabited mainly by non-combatants by dropping more than 1,000 bombs, causing lots of fires and countless deaths.

The Japanese bombing also hit the Chinese cities of Changsha, Yangzhou, and Yichang, according to the archives.

The Jilin Provincial Archives has recently released 450 wartime documents revealing atrocities Japanese troops committed in China during World War II. These documents, including 45,000 letters, were all recorded in Japanese during the period from 1937 to 1945.

The files were collected by the Japanese military police during its invasion of China, said Yin Huai, president of the Jilin Provincial Archives.

They secretly checked publications and letters, telegrams, phone conversations between Japanese servicemen, Japanese immigrants and other foreign nationals, and then copied and filed those detailing the Japanese army's atrocities and details about the war so as to report to the Japanese high military commanders before deleting, seizing or burning the records, Yin said.

Yin said these documents were vivid evidence based directly on the experiences of Japanese invaders and were compiled by the Japanese military police themselves, making them original, real and objective.

(Xinhua News Agency July 2, 2014)