An explosion occurred Monday near the U.S. military’s Kadena Air Base in the southern Japanese prefecture of Okinawa, slightly injuring four Japan Ground Self-Defense Force members who were working at a depot, local and Defense Ministry officials said.

The ministry officials said there was an unidentified explosion while SDF personnel were preparing for bomb disposal operations, causing those in close proximity to suffer finger lacerations and possible hearing damage.

The explosion appears to have occurred at an SDF storage facility for unexploded bombs in the ammunition depot area of the base, a Defense Ministry source said.

According to local authorities, no evacuation order has been issued for nearby residents, and there is no risk of further explosions or fire.

Okinawa remains home to the bulk of U.S. military facilities in Japan even after its 1972 reversion from U.S. control following Japan’s defeat in World War II.

Photo taken from a Kyodo News airplane on Dec. 8, 2023, shows the U.S. Air Force’s Kadena Air Base in the southern Japan island prefecture of Okinawa. (Kyodo) ==Kyodo