A warehouse which caught fire after an explosion is seen at the US Army Sagami General Depot in Sagamihara, southwest of Tokyo, Japan, in this aerial photo taken by Kyodo August 24, 2015. [Photo/Agencies]

TOKYO - Multiple explosions and a large fire at a US Army depot lit up the night sky in a Tokyo suburb early Monday. No injuries were reported.

The blast happened after midnight at the Sagami General Depot in Sagamihara, a city about 25 miles (40 kilometers) southwest of Tokyo, said Navy Commander Bill Urban, a Pentagon press officer.

The building that exploded was storing compressed nitrogen, oxygen, Freon and air, a statement issued by the US Army Japan said. Photos taken after daybreak and released by the Army show dozens of gray canisters lying on the floor, and what looks like mangled storage racks.

The walls of the one-story, concrete building remain intact, but the windows and doors are damaged and about half of the roof collapsed, the Army said. There are no indications of injuries.

Video on Japanese television, apparently shot from an elevated place outside the post, shows a fire in the distance and subsequent explosions shooting small fiery blasts into the sky. A woman told national broadcaster NHK that it sounded like fireworks.

About 580 people work at the 200-hectare (500-acre) depot, NHK said.

Base firefighters were joined by Japanese emergency responders in fighting the fire to present its spread to nearby buildings, the Army said.

"The Army appreciates the quick reaction and support of our partners from the Sagamihara City emergency services," said an earlier statement from US Army Japan.

The cause of the explosion is under investigation.