A U.S. Army depot building in Japan exploded just after midnight local time on a base about 25 miles southwest of Tokyo, U.S. military officials said.
The Army does not know what caused the fiery incident in the city of Sagamihara, but no injuries were reported.
Photos and video of the event quickly rippled across social media with posts on Twitter, Facebook, and YouTube of a thunderous explosion followed by a ball of fire that lighted up the night sky.
U.S. Pacific Command, which oversees U.S. military operations in the region, confirmed the explosion happened at Sagami general depot early Monday morning.