West Bengal Governor Jagdeep Dhankhar here on Saturday sought an "intense expert probe" and prompt fixing of administrative accountability in the blast at a Naihati fireworks manufacturing unit that left four dead and one injured.

The factory owner, Noor Hossain, has been arrested.

Stating that the deaths "pained" and "shocked" him, Dhankhar tweeted, "Allegations that crude bombs were being made in the illegal factory warrants intense expert probe. Accountability of all in the administration needs to be fixed promptly."

Four employees, including two women, of the factory in the 24 Parganas North district were killed while the wounded man was being treated for severe burn injury at the Kalyani J.L. Nehru Hospital following Friday's explosion, the police said.

The factory owner has been charged under a number of non-bailable sections, including culpable homicide not amounting to murder.

While the cops are looking into the causes of explosions, the Bharatiya Janata Party (BJP) has demanded probe by the National Investigation Agency (NIA).

"We want NIA probe. Bombs were being manufactured in the factory," said BJP MP Arjun Singh.