BJP National Secretary Sidharth Nath Singh, who is also the state in-charge, also rejected the state police version in the last week's Pingla blast in which 12 people were killed and said it was an evidence of "terror infrastructure spreading" in the state.
At least 14 passengers were injured when an explosion took place inside a compartment of Sealdah-Krishnanagar local train early this morning.
"The explanation given by the state police regarding the train blast is a mere cover. It lacks logical reasoning. In the early hours at 3.55 AM two rival groups will not board a train to hurl bombs and settle their scores.
The state government should come out with a credible defence, Singh said, in a dig at the Mamata Banerjee government.
"BJP demands that a central investigation agency like NIA should look at all these incidents more holistically. Already NIA in their Burdwan chargesheet has pointed to terror activities spreading in the districts of Birbhum, Nadia, Burdwan and Murshidabad," he said.