TOKYO — A regional airport in southwestern Japan was closed Wednesday after a U.S. bomb, most likely dropped during World War II to curb “kamikaze” attacks, exploded near its runway, causing nearly 90 flight cancellations.

Miyazaki Airport closed its runway after the explosion caused a 23-foot-wide and nearly 3-foot-deep crater in the middle of the taxiway next to the runway, according to a Japanese Transportation Ministry official.

A bomb disposal team from the Japan Ground Self-Defense Force later determined that the cause of the explosion was an American bomb buried beneath the land surface, which was likely the result of a wartime air raid, the official said.

No injuries were reported, but live cam footage showed a plane taxiing nearby just two minutes before the explosion, according to local broadcaster MRT.

The runway closure has led to the grounding of 87 flights, but there is no risk of further explosions and repair work to fill the hole should be completed by Thursday morning, Japan’s top government spokesman Yoshimasa Hayashi said.

According to the airport’s website, the affected flights were operated by JAL, ANA and other airlines connecting Miyazaki to cities such as Tokyo, Osaka and Fukuoka.

Located on the southeastern end of Kyushu Island, Miyazaki Airport was a Japanese naval base until the end of World War II, from which hundreds of young “kamikaze” pilots set off on their final missions, according to the city of Miyazaki’s website.

Several unexploded bombs have already been found at Miyazaki airport, the transportation ministry official said.

More than 79 years after the end of the war, unexploded bombs from the intense air raids are still being found all over Japan.

According to the Self-Defense Forces, a total of 2,348 bombs weighing 41 tons were disposed of in fiscal year 2023.