A Chinese woman forced into front-line brothels for Japanese troops during World War II died on Saturday, bringing the number of surviving "comfort women," a euphemism for sex slaves, to only 14 on the Chinese mainland.

Huang Youliang died at the age of 90 at her home in Yidui Village in China's southern island province of Hainan.

In October 1941, 15-year-old Huang was raped when the Japanese troops invaded her hometown. She was later put into a brothel and forced to have sex with Japanese soldiers for two years.

In July 2001, Huang and seven other "comfort women" sued the Japanese government, demanding an apology, but the Japanese court repeatedly rejected their appeals over the past decade, claiming that individuals have no right to sue the state.

Women forced into sexual slavery by the Imperial Japanese Army before and during World War II were called "comfort women." Research shows some 400,000 women in Asia were forced to be "comfort women" for the Japanese army during World War II, nearly half of whom were Chinese.

However, the Japanese government has refused to acknowledge legal responsibility for the "comfort women" issue so far.

Efforts by a total of 24 Chinese "comfort women" to sue the Japanese government in four cases since 1995 all failed. Huang is also the last victim to have sued the Japanese government over sex slavery on the Chinese mainland, according to Su Zhiliang, director of a research center on comfort women under the Humanities and Communication College of Shanghai Normal University.

Huang's passing means there are only 14 registered "comfort women" on the Chinese mainland.