This is the dramatic moment a WWII bomb exploded next to the runway forcing flight cancellations at an airport in Japan on this morning.

The ordnance is believed to have been dropped by the Allies to blitz kamikaze fighters from the Far East supporting the Nazi advance on the West lead by Adolf Hitler of Germany.

However, it is said to have remained infected fore some 80 years before the blast today at the Miyazaki Bougainvillea Airport in the Miyazaki Prefecture.

CCTV captured the blast as a plane was preparing for take-off. Officials said a bomb disposal team from the Japan Ground Self-Defence Force later investigated. They reportedly found that the cause of the explosion was an American bomb that had been buried beneath the land surface, probably dating to a wartime air raid.

Government spokesman Yoshimasa Hayashi said the runway was shutdown and 87 flights were cancelled. He said there was 'no danger' of further explosions.