Thirteen Chinese filed a damages suit Tuesday against the Japanese government and Mitsubishi Materials Corp., seeking a combined 184 million yen for being used as forced laborers during World War II.

In their lawsuit filed with the Miyazaki District Court, the 13 -- seven former slave laborers and six relatives of laborers who have died -- also demand that the defendants officially apologize to them.

According to the complaint, Shao Changshui, 77, and the others were rounded up by the Imperial Japanese Army in 1944 in China and forced to work in the Makimine copper mines in Miyazaki Prefecture.

The mines were operated by Mitsubishi Mining Co., which later merged with another group company to become the present-day Mitsubishi Materials.

The Chinese labored under unsanitary conditions with little food, and many of them suffered skin diseases as a result of their environment, the complaint noted.

Some 250 Chinese were forcibly brought over to the Makimine copper mines, mainly from Shandong Province, in the closing days of the war. Of them, 77 died from disease or were shot and never made it back to their homeland.

Rulings on Chinese slave labor cases vary, with the Hiroshima High Court in July ruling in favor of Chinese plaintiffs while the Fukuoka High Court in May ruled against Chinese forced laborers.