Two police officers who responded to a garage fire in Northeast Philadelphia were injured early Monday when an explosion went off inside the building.

The Philadelphia Fire Department said the blaze in a garage on the 1100 block of Arrott Street in Northwood was reported at 1:25 a.m. and crews encountered heavy flames on arrival.

There was some type of explosion in the garage, sending fragments of a vehicle flying and injuring two officers who had responded to the scene.

The officers were treated at Aria Health's Frankford Campus and released, police said.

The blaze was declared under control at 1:42 a.m., the fire department said.

The cause of the fire is under investigation.