TOKYO (AP) — About a dozen people protested outside Mitsubishi Heavy Industries headquarters in Tokyo on Friday, demanding Japanese companies pay compensation for their wartime abuse of Korean laborers.

The protesters called on the companies to accept South Korean supreme court ruling two years ago that severely strained relations between the two neighbors. That court on Oct. 30, 2018, ordered Nippon Steel & Sumitomo Metal Corp. to compensate four plaintiffs for their wartime forced labor at the company.

The court a month later made a similar ruling on Mitsubishi Heavy Industries, deepening tensions between the two countries. South Korea's bitter memories of Japanese atrocities during its 1910-1945 colonial rule of the Korean Peninsula and compensation issues have been a recurring strain on bilateral ties.

Friday's protest was organized by three Japanese civil groups supporting the Korean plaintiffs and seeking settlements of other wartime abuses.

Standing outside the Mitsubishi headquarters building, the protestors held up a sign saying “Nippon Steel and Mitsubishi comply with the supreme court ruling."

Japan maintains that all wartime compensation issues were settled by a 1965 treaty and that South Korean rulings violate international law. Japanese courts have also rejected compensation demands by South Korean plaintiffs.

Mitsubishi and Nippon Steel have said they were cooperating with the Japanese government.

Historians say Japan used about 220,000 wartime Korean forced laborers.

Japan acknowledged its wartime aggression and apologized to Asian victims in 1995, but has since significantly backpedaled under former Prime Minister Shinzo Abe’s nationalistic government that lasted nearly eight years.

The latest dispute spilled over into trade and military issues, complicating cooperation between the two key American allies.

Prime Minister Yoshihide Suga, who replaced Abe after he stepped down due to health issues in mid-September, has said Japan's position on the compensation is unchanged and says Seoul should take appropriate actions to restore “healthy” bilateral relations.

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