Kolkata, Jul 4 (IANS): A massive blast occurred at a primary health centre building in the wee hours of Thursday in West Bengal's Birbhum district but there was no report of any casualty, police said.

The severity of the blast was such that the roof and wall of one side of the building at Labhpur were blown away.

"The building of Dwarka health centre was blown off due to an explosion around 2:45 a.m. We are at the spot investigating the matter and there is no report of any injury or casualty," an officer of Labhpur police station said.

An employee of the health centre said they were lucky that the incident occurred at night but there is an atmosphere of fear all around. Incidentally, the health centre is barely a few metres away from the police station.

On June 29, another explosion inside the club building at Mollarpur had blown away the walls and damaged some of the houses in the vicinity. A local BJP leader said that there should be proper investigation of these blasts, while Trinamool Congress members feel that the BJP is responsible.

"We want the NIA to investigate, not just the police or CID of West Bengal Police," the BJP leader said.