Miyazaki Airport, near where unexploded ordnance leftover from World War II have been discovered in the past, canceled all flights on Wednesday after a minor unexplained explosion was reported there.
There were no reports of injuries from the incident at Miyazaki Airport early Wednesday.
The blast appeared to have happened at least 100 meters away from the terminal building, footage on Japanese media showed.
A local fire department “received a call from the airport at 7:59 a.m. that there was an incident involving smoke,” its spokesperson said.
He quoted airport staff as saying something “might have exploded, although it’s not confirmed.”
An airport official, meanwhile, gave no further details, saying only that part of a taxiway had caved in and that flights were canceled until the evening.
The official, Takehiro Maeda, said police and the fire department were investigating.
Japan Airlines said the incident prompted the cancelation of 13 flights that should have carried 790 passengers.
Miyazaki airport originated in 1943 as an Imperial Japanese Navy base, sending dozens of kamikaze aircraft on suicide missions.
Unexploded ordnance thought to have been dropped by the United States during the war was found at a nearby construction site in 2009 and 2011, the Mainichi Shimbun daily reported.