MOSCOW (AP) — A warehouse holding a reported 15 metric tons (16.5 tons) of fireworks in central Moscow caught fire on Saturday, sending a huge cloud of smoke and a fusillade of explosions over the area.

Three firefighters and a warehouse employee were injured and one firefighter was hospitalized.

Three helicopters and a fireboat were dispatched to help put out the blaze at the warehouse, which sits 100 meters (320 feet) from the Moscow River near the sprawling Luzhniki sports complex.

The cause of the fire was not immediately determined.