A Korean woman who was forced into sexual servitude by Japan's World War II soldiers died Monday, an advocacy group for these former sex slaves said Monday. She was 89.

Hwang Seon-sun died at a hospital in South Jeolla Province at around 8 a.m., the Korean Council for Women Drafted for Military Sexual Slavery by Japan said. The group attributed her death to old age without elaborating further.

Hwang's death lowered the number of known survivors to 54, the council said.

Hwang was born in 1926 in Jangseong, a rural town some 300 kilometers south of Seoul. Her parents died early, leaving her responsible for the care of her younger brother.

At 17, she found herself in Japan's front-line military brothel after a neighbor lured her with promises of a job at a factory in Busan, the second-largest city in South Korea.

She was stationed at a brothel in Nauru, a Pacific island then occupied by Japan, and was beaten and tortured regularly for three years until the Japanese surrendered in 1945.

Historians estimate there were about 200,000 sex slaves from all over Asia. Most of them are believed to have been Korean, though the South Korean government only has 238 in its database.

After Korea's independence, Hwang returned to her hometown to live with her son and daughter-in-law. Life after the war, however, was not easy for the woman, as she constantly suffered from diseases such as cerebral infarction and diabetes, the council said.

Her funeral will be held in private on Wednesday, according to her family's wish, the council added.

Monday also marked the one-year anniversary of the death of another Korean sex slave, Hwang Geum-ja, who died at 90. (Yonhap)