A bomb dropped by the US in World War II explodes at an airport in Japan, causing runway damage and the cancellation of 80 flights.

A US bomb that had not exploded since World War II and had been buried at a Japanese airport exploded on Wednesday, creating a large crater on a taxiway and grounding more than 80 planes but causing no injuries, Japanese officials said.

Land and Transport Ministry officials said there was no plane nearby when the bomb exploded at Miyazaki Airport in southwestern Japan.

Officials said that an investigation by the Self-Defense Forces and the police confirmed that the explosion was caused by a 500-kilogram American bomb and that there was no danger. They were determining what caused its sudden explosion.

Video recorded by a nearby flight school showed the explosion spewing chunks of tar into the air like a fountain. Videos broadcast on Japanese television showed a crater in the taxiway that was reported to be about 7 yards wide and 3 feet deep.

Chief Cabinet Secretary Yoshimasa Hayashi said more than 80 flights have been canceled at the airport, which is expected to resume operations on Thursday morning.

“There is no threat of a second explosion, and the police and firemen are currently examining the scene,” said Hayashi.

The fire department “received a call from the airport at 7:59 a.m. that there was an incident involving smoke,” a spokesman told AFP.

Miyazaki Airport was built in 1943 as an aircraft training ground for the Imperial Japanese Navy from which kamikaze pilots took off for suicide attacks.

Dozens of unexploded bombs dropped by American soldiers during World War II have been unearthed at the site, Defense Department officials said.

Another unexploded ordinance dropped by the United States was reportedly found at a nearby construction site in 2009 and 2011.

Hundreds of tons of unexploded bombs from the war remain buried around Japan and are sometimes dug up in construction sites.

2,348 bombs weighing 41 tons were dropped in fiscal year 2023, Reuters news agency reported, citing the Self-Defense Force.

Last year, a World War II bomb was found in England it exploded in what authorities call a “random” explosion.

AFP contributed to this report.