An explosion rips through a US military facility in the Japanese city of Sagamihara in the north-central Kanagawa Prefecture near Tokyo, the Japanese Broadcasting Corporation (NHK) reports.

Photos and video footage released online on Sunday apparently show several explosions at Sagami General Depot, a US base used for the storage of fuel and munitions.

“I was asleep, and at first thought it might have been the roar of thunder, but then there was a sequence of explosions for 10, maybe 15 minutes. A pillar of orange rose to the skies, and the air was filled with the smell of gunpowder,” NHK quoted an eyewitness as saying.

The national broadcaster NHK quoted the fire department of Sagamihara as saying that the explosions took place shortly before 1:00 am Monday local time.

American military authorities reacted to reports of the blast and the ensuing fire on early Monday.

“There are no reports of injury, and base firefighters and first responders are currently fighting the resulting fire to prevent its spread to nearby buildings," said US Navy Commander Bill Urban.

Urban noted that the depot did not store ammunition or radiological material and that, “we are in the process of determining the exact contents of the building."

According to AFP, Japanese fighters are still waiting for US information on the warehouse’s contents before tackling the fire.

"We are coordinating with US fire units and we are waiting for people who know exactly what is inside to tell us what's inside," said a duty officer at the Sagahimara fire bureau."We have not poured water (on the warehouse) because it could make the situation worse, depending on what is inside."

More than ten fire trucks have been deployed to the site of the fire.

Japan’s Asahi said that no general evacuation of nearby areas had been called.

Surrounded by urban area, the site houses the 35th Combat Sustainment Support Battalion, as well as logistical and medical departments for the US military in the region.

In recent years, the underused base has been the subject of negotiations.

Back in April, three explosions blamed on an extremist group were reported in the vicinity of the base.