Yoshio Karino was 11 when he helped to beat an American airman to death in the closing days of the Second World War, while Yasuhiro Hamada was just two years older.

Today, more than seven decades later, the two men have broken their silence on an incident that the people of Tachikawa would prefer to forget.

The death of the US airman, identified as Staff Sgt. Serafino Morone, a member of the crew of a B-29 Superfortress shot down on a bombing raid just days before Japan's surrender, has never been recorded in any official history of this suburb of west Tokyo.

Interviewed by the Asahi newspaper, Mr Karino, now 82, and Mr Hamada say they decided to recount their experiences in an effort to show how civilians had been indoctrinated to despise the enemy.

"The US military had been conducting bombing raids, so everyone was likely angry at the Americans," Mr Karino said.

So when an airman who had parachuted from his crippled bomber was captured, local residents lined up to abuse him.

Mr Karino said he was among "hundreds" of people who took turns "viciously beating" Staff Sgt. Morone, from Pennsylvania, in the grounds of a local school from midday on August 9, 1945.