An explosion occurred at the northern section of a munitions storage area on Kadena Air Base, Okinawa, June 9, 2025. (Keishi Koja/Stars and Stripes)

Four Japanese soldiers were injured Monday in an explosion at a munitions storage area on Kadena Air Base, Okinawa, according to U.S. Air Force and local officials.

The blast occurred in the northern section of the site as workers were removing rust to help identify unexploded ordnance, the Yomitan Fire Department said in a news release. The facility is primarily used to store munitions left over from World War II.

The fire department said it received the report at 11:17 a.m. One man in his 40s suffered minor to moderate injuries to his left hand, while three others reported minor injuries, including hearing issues. One of the injured soldiers also suffered scratches on his right arm and left cheek.

All four are members of the Japan Ground Self-Defense Force and were taken to an off-base hospital, a fire department spokesman said by phone.

The facility is managed by the Okinawa Prefectural Government, according to a statement from Kadena’s 18th Wing. No U.S. personnel were involved in the incident, a follow-up statement said.

There was no risk of fire, a spokesman with the prefecture’s Disaster Prevention and Crisis Management Division said by phone. Prefectural officials were dispatched to the scene to investigate the incident, he said.

Japanese government officials sometimes speak to the media on condition of anonymity.

Unexploded ordnance from the 1945 Battle of Okinawa is still regularly found across the island, particularly at former battlefield and construction sites.

Between April 2023 and March 2024, crews disposed of nearly 22 tons of WWII-era ordnance on Okinawa, according to the Okinawa General Bureau website.