India, Jan. 11 -- One person was killed and three others were critically injured after an explosion rocked a firecracker factory in Champahati area of West Bengal's South 24 Parganas district on Saturday night, the police said.

"One of the injured, identified as Gourhari Banerjee (60), died in the hospital in the early hours of Sunday. The Baruipur police have registered a suo motu case to find out the cause and whether the factory had a licence," a local police officer said, requesting anonymity.

The explosion ripped through the factory at Champahati, an old hub of fireworks makers, and set the house on fire.

Locals told the police that all four men were inside the house where illegal crackers were being made.

Two of the injured were...