According to the indictment, Shirosaki conspired to fire two mortar shells towards the Japanese Embassy from a hotel room in the Indonesian capital of Jakarta on May 14, 1986. Nobody was injured in the incident as the bombs did not explode.

He is also suspected of using someone else’s passport at a local hotel and a car rental company.

In the opening statement, prosecutors said fingerprints were found in the hotel room. But Shirosaki’s defence lawyers said he was not in Indonesia at the time and had been in Lebanon since 1977, adding that the fingerprints could have been collected at another site.

Shirosaki was arrested in Japan for attempted bank robbery and sentenced to a 10-year term in 1971. He was released in 1977 along with other radicals in exchange for hostages taken by the group in the hijacking of a Japan Airlines jetliner in the Bangladesh capital of Dhaka.

In the first lay judge trial dealing with a case involving a radical group, 21 hearings are expected before its conclusion on November 1. A total of 23 witnesses including a former Federal Bureau of Investigation official are set to be questioned.

In 1996, Shirosaki was arrested and handed over to US law enforcement authorities in Nepal, where he had been in hiding, for a mortar attack on the US Embassy in Jakarta in 1986, and extradited to the United States.

A US court sentenced him to 30 years in prison in 1998 for attempted murder and other crimes in connection with the mortar attack. His jail term was shortened for good behaviour and was released in January last year.

When he returned to Japan the following month, Tokyo police arrested him for alleged arson and attempted murder in connection with the 1986 mortar attack. The Japanese Red Army staged a series of indiscriminate attacks in various parts of the world in the 1970s and 1980s including a 1972 shooting rampage at Tel Aviv airport in Israel that killed 26 people and injured dozens of others.