A US bombshell blast leaves a huge crater at Miyazaki Airport, prompting cancellation of nearly 90 flights.

The detonation of a US bombshell, likely dropped during World War II, has forced the closure of a regional airport in Japan.

The buried armament exploded near the runway of Miyazaki Airport on the southern Japanese island of Kyushu on Wednesday. The blast damaged a runway, grounding all 87 flights scheduled for the day.

Miyazaki, which was used as a base for “kamikaze” pilots, shut its runway early on Wednesday after a blast left a crater seven metres (23 feet) wide and one metre (3.2 feet) deep in the middle of the taxiway, an official of the Ministry of Land, Infrastructure, Transport and Tourism said.

A bomb disposal team from the Japan Ground Self-Defense Force later found that the cause of the explosion was a US bomb that had been buried beneath the land surface, probably dating to a wartime air raid, the official added.

No injuries were reported, but live camera footage showed an aeroplane had been taxiing near the blast site, which was about 100 metres (109 yards) away from the terminal building, shortly beforehand, according to local broadcaster MRT.

Government spokesperson Yoshimasa Hayashi said the runway is expected to be reopened on Thursday morning after repair works to fill the hole are completed.

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.

‘Kamikaze’ base

Miyazaki Airport was a Japanese navy base from 1943 until the end of World War II, from where hundreds of young “kamikaze” pilots set off on their final missions, according to the Miyazaki city website.

Multiple unexploded US bombs have previously been found at the airport, the transport ministry official noted.

More than 79 years since the end of the war, unexploded bombs from the intense air strikes are still found across Japan today.

A total of 2,348 bombs weighing 37.5 tonnes were disposed of during fiscal year 2023, the Self-Defense Forces have said.