KOLKATA: At least four persons, including three women, died in an explosion at a firecracker manufacturing unit in Nadia district of West Bengal on Friday, police said.
Another woman suffered injuries in the explosion at the factory located in a congested residential area of Rathtala in Kalyani, they said.
"Four persons were rescued from the blast site, and later declared dead when taken to the nearby JNM Hospital. The condition of the injured woman is critical," a senior police officer said.
"We are trying to ascertain the identity of the deceased and the injured person, and whether they were workers in the factory," he said, adding, the cause of the blast is not yet known.
A team of forensic team experts is on their way to the spot, the officer said.
A blaze that erupted in the unit following the explosion was brought under control by firefighters after around one-and-a-half hours, police said.
Further investigation is underway.