Relatives of four deceased South Koreans who were forced laborers at a steel mill in northern Japan during World War Two failed on Wednesday to overturn a Japanese court decision refusing compensation for unpaid wages.

The result, in line with most Japanese rulings on war-related compensation claims, comes at a time when Japan's ties with South Korea and China have been chilled by disputes stemming from Japan's past aggression in Asia.

In Wednesday's case, Tokyo High Court rejected an appeal from a lower court in which the relatives demanded that the Japanese government be ordered to pay 20 million yen ($166,600) in compensation for each of the four, Kyodo news agency said.

"It is legitimate to reject the case as it is clear that the right to file claims has been nullified," Presiding Judge Hiromu Emi was quoted by Kyodo as saying.

A court official confirmed that the appeal had been rejected but declined to give further details.

The court upheld an October 2004 ruling that said property claims by South Koreans who were forced to work in wartime Japan had been nullified under a 1965 treaty that normalized relations between the two countries, Kyodo said.

It said the court heard that the four deceased South Koreans were forcibly brought to Japan and made to labor at an ironworks in the city of Kamaishi, about 400 km (250 miles) north of Tokyo, for Japan Iron & Steel Co. -- now known as Nippon Steel Corp. They died in an Allied naval bombardment in July 1945, it said.

Japan says the issue of wartime compensation claims with South Korea was settled in the 1965 treaty, which required Japan to pay $500 million in economic aid to South Korea.