South Korea's Supreme Court on Thursday upheld lower court rulings that ordered Japanese firms to pay damages to plaintiffs who sued them over wartime labor.

Thursday's rulings were for three lawsuits against Mitsubishi Heavy Industries and Hitachi Zosen.
The plaintiffs were South Korean former workers who said they were forced to work for the firms during World War Two, as well as their bereaved relatives.

Lower courts had ruled in the plaintiffs' favor. The Japanese companies had appealed the rulings.

Japan says any right to claims was settled by a bilateral agreement in 1965 when the two countries normalized ties.

The South Korean top court on Thursday said the right of individuals to seek compensation is not covered in the 1965 agreement. It finally confirmed the rulings to order the Japanese firms to pay compensation.

The Supreme Court last Thursday upheld similar compensation orders issued by lower courts in two other wartime labor cases.

A group supporting the plaintiffs said the Supreme Court is now handling four similar wartime labor disputes against Japanese firms. The group says more than 60 such cases are ongoing in lower courts.

In March, South Korea's government announced a scheme in which a government-affiliated foundation would pay damages to plaintiffs in place of Japanese firms. The government has said it will apply the scheme to plaintiffs in the series of similar lawsuits for which compensation orders have been finalized.

In Tokyo, Director-General of the Japanese Foreign Ministry's Asian and Oceanian Affairs Bureau Namazu Hiroyuki lodged a protest with South Korea's Embassy over the matter.

Namazu summoned senior embassy diplomat Kim Jang-hyun to the Foreign Ministry and said Thursday's and last week's rulings clearly go against the 1965 agreement and are totally unacceptable.

The Japanese official said the cases should be dealt with accordingly based on the South Korean scheme to have an affiliated foundation pay damages to the plaintiffs.