Haruo Wako, a former Japanese Red Army militant group member sentenced to life imprisonment for his role in the seizure of foreign embassies overseas in the 1970s, has died, sources close to the matter said Monday. He was 75.

Wako died of unknown causes on Saturday at Osaka Medical Prison in western Japan after being transferred to the facility from Tokushima Prison, where he was serving his life sentence, the sources said.

Wako was convicted for his involvement in the seizure of the French Embassy in The Hague with other members of the leftist revolutionary organization in September 1974, taking the ambassador and other staff hostage. They also shot two police officers, seriously injuring them.

In August 1975, he was also involved storming a building housing the U.S. Embassy in Kuala Lumpur and firing at police officers in an attempt to force the Japanese government to release some fellow members of the now-disbanded group.

Wako, detained in Lebanon in 1997 and deported in 2000, was subsequently arrested in Japan on charges of attempted murder and abduction in connection with the cases.

In 2009, the Supreme Court rejected Wako's appeal, finalizing his life sentence.

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