BEIJING - China's bar association has condemned a Japanese court ruling which rejected claims for an apology and compensation by eight Chinese women who said they were forced to act as sex slaves for Japanese soldiers during World War Two.

The verdict by a Tokyo court on Wednesday was a serious setback as it ignored the nature of the offence, the All China Lawyers Association said in a statement published in state media on Thursday.

"It did not admit that the forced sex slavery was a crime," the Xinhua news agency quoted the statement as saying.

Relations between China and Japan are at their lowest ebb in decades over a series of disputes, most springing from Japan's 1931-45 invasion and occupation of parts of China. On Wednesday, China rebuked Japan for protesting over its exploration of a disputed gas field in the East China Sea, asking Tokyo not to make more trouble.

The eight women, who had said they were used as sex slaves by Japanese soldiers occupying China's southern province of Hainan, had sought a total of 184 million yen ($1.58 million) in compensation from the Japanese government. Two of the eight have since died.

The women were in their teens at the time and some were confined for about three years, they said in their lawsuit.

The bar association and other Chinese civic organisations have set up a committee which will investigate the slavery issue over the next five years.

The verdict ended the last compensation lawsuit at the district court level in Japan, the plaintiffs' lawyers said.

Historians differ on the number of sex slaves -- estimates run from 20,000 to 200,000 -- but many agree that women from various parts of Asia were forced to work in brothels for the Japanese military before and during World War Two.

The Japanese government has set up a fund to provide financial aid to the women, but it contends all issues of compensation were settled by peace treaties after the war.

There have been 10 lawsuits filed involving sex slaves filed before Japan courts. Seven had already been dismissed and two are still being tried at the Supreme Court, Kyodo news agency said.

($1=116.76 yen)