TOKYO (BN24) — An explosion at a facility for storing unexploded ordnance on a U.S. air base in Okinawa injured four Japanese soldiers on Monday, Japanese and American officials said. The injuries are not believed to be life-threatening.

The blast occurred at a site managed by the Okinawa prefectural government within the munitions storage area of Kadena Air Base, the U.S. Air Force said in a statement. No U.S. military personnel were involved in the incident, according to the statement.
Local authorities said the explosion happened while members of Japan’s Ground Self-Defense Force were inspecting unexploded wartime ordnance. The soldiers were reportedly removing rust from one of the devices when it suddenly detonated, NHK television reported. All four sustained injuries to their fingers.
Okinawa prefectural officials confirmed the injuries but said further details about the cause of the explosion remain under investigation.
The Self-Defense Forces Joint Staff said the incident marked the first such accident since the creation of Japan’s unexploded ordnance disposal unit in 1974.
Thousands of tons of unexploded munitions, mostly dropped by U.S. forces during World War II, remain buried across Japan — particularly in Okinawa, where some of the fiercest battles of the war were fought. Officials estimate that approximately 1,856 tons of unexploded bombs still remain on the island.
Such ordnance is frequently discovered during construction work. In a separate incident in October, an unexploded U.S. bomb detonated near a commercial airport in southern Japan, forming a large crater and causing the suspension of dozens of flights.
Monday’s blast underscores the ongoing dangers posed by wartime remnants more than seven decades after the end of World War II.