Almost 100 flights have been cancelled after an unexploded US bomb that had been buried at a Japanese airport exploded. The bomb, dating from the Second World War, caused a large crater in a taxiway. No-one was injured in the incident at Miyazaki Airport in south-western Japan , officials said, adding that more than 80 flights had to be cancelled.

The affected flights were operated by JAL, ANA and other airlines connecting Miyazaki with cities such as Tokyo, Osaka and Fukuoka, according to the airport website. Land and transport ministry officials said there were no aircraft nearby when the bomb exploded. Officials said an investigation by the Self-Defence Forces and police confirmed that the explosion was caused by a 500lb US bomb, and there was no further danger.

They were determining what caused its sudden detonation. A video recorded by a nearby aviation school showed the blast spewing pieces of tarmac into the air like a fountain. Videos broadcast on Japanese television showed a crater in the taxiway reportedly about 21ft in diameter and 3ft deep.

Chief cabinet secretary Yoshimasa Hayashi said more than 80 flights had been cancelled at the airport, which hopes to resume operations on Thursday morning. Miyazaki Airport was built in 1943 as a former Imperial Japanese Navy flight training field from which some kamikaze pilots took off on suicide attack missions. A number of unexploded bombs dropped by the US military during the Second World War have been unearthed in the ar.