BEIJING -- Confessions by Japanese war criminals released Thursday revealed Chinese women and underage girls were forced by the Japanese army to work as comfort women during Japan's World War II invasion.

According to the 1954 confession of Seki Inaba, who served as the communications officer of the invading Japanese army, a squadron commander ordered 20 women and girls aged 17 to 20 to be taken from those captured in a village attack in Shanxi Province in March 1945 to serve in a "comfort station."

The account of an officer named Hayato Murayama showed his troops recruited seven Chinese women as prostitutes for a comfort station in Shanxi Province in October 1944. He admitted to raping a 15-year-old girl when the station opened.

Confessions documenting Japan's WWII atrocities also include one by Masao Watanabe. The Japanese munitions officer recounted that Japanese troops lured and imprisoned about 50 Chinese women and girls aged 16 to 25 from May 1942 to March 1944 in Shandong Province.

The victims were subjected to "the greatest material, mental and physical sufferings in the world," according to Watanabe's confession.

Tuesday's release by China's State Archives Administration (SAA), is the sixth installment in an eight-part series of videos and archives documenting the suffering of sex slaves at the hand of the Japanese military over 70 years ago.

The documents are available at the SAA's website.