Koreans who were forced into slave labour in Japan during World War II sued six Japanese companies and their U.S. subsidiaries on Tuesday, seeking reparations for thousands of unpaid Korean labourers.

The plaintiffs, who filed their lawsuit in a Los Angeles Superior Court and announced it at press conferences there and in Seoul, seek compensation for their unpaid labour as well as damages for pain and suffering.

The lawsuits were filed against Mitsubishi Heavy Industries, Mitsubishi Materials Corp, Mitsui & Co, Mitsui OSK Lines, Mitsui Mining Co., Mitsui Mining and Smelting Co and their U.S. subsidiaries.

Plaintiffs lawyer Barry Fisher said the lawsuits will seek class-action status to represent the thousands of people forced into slave labour between 1929 and 1945 to win them what he said was long-overdue compensation.