The death toll in the explosion at an 'illegal' fire-cracker factory at Egra in East Midnapore district on Tuesday has risen to nine.
Thirteen other critically injured persons are currently undergoing treatment at a local hospital.
Meanwhile, the local people staged a protest after some senior police officers of the district reached the spot on Tuesday evening. There were heated exchange of words and even scuffles between the protesters and the cops.
The protesters alleged that it was because of the indulgence of the local police that such illegal fire-cracker factories were mushrooming in the area, which is close to the Bengal-Odisha border.
However, the large police contingent present there quickly brought the situation under control.
Meanwhile, West Bengal BJP President Sukanta Majumdar has written to Union Home Minister Amit Shah seeking a probe into the matter by the National Investigation Agency (NIA).
Chief Minister Mamata Banerjee has also said that she has no objections to an NIA probe into the matter.
Majumdar has claimed that the impact of the blast shows that it was not an explosion of ordinary fire-crackers.
"We suspect that crude bombs were being manufactured in the factory," he said.
As the police suspect that the owner of the illegal fire-cracker factory, Krishnapada Bag, might have escaped to adjacent Odisha, the officers of the Criminal Investigation Department (CID) of West Bengal police have contacted their counterparts in Odisha, alerting them about the absconding suspect.
Earlier on Tuesday, the Chief Minister said that Bag was arrested on charges of running an illegal fire-cracker factory in October last year.
"The police even filed a charge sheet against him. But the court granted him bail. After that he again started this illegal fire-cracker factory in the area which is close to Bengal-Odisha border," Banerjee said.