A huge explosion has hit a Quebec fireworks warehouse in Canada, killing two people, provincial police have said.The incident took place on Thursday in B.E.M. Fireworks near Valleyfield, a city in southwestern Quebec, leaving a huge cloud of smoke behind, The Associated Press reported. The initial powerful blast was followed by a series of smaller explosions. Police said two bodies -- believed to be factory employees -- were found in the wreckage of the building. Local fire chief Stephane Massicotte said 50 firefighters were used to battle the flames, which were under control by early Thursday afternoon. Dozens of people were evacuated from nearby homes after the fire erupted. A nearby highway was also closed in both directions. Police say the cause of the explosion is under investigation.