Kolkata, July 8 (IANS): The National Investigation Agency (NIA), probing the Burdwan blast, has been directed to investigate the explosion in a suburban train in West Bengal's North 24-Parganas district, suspecting a terror link.

The explosion occurred in a compartment of the Sealdah Krishnanagar local train near Titagarh station in the district.

At least 18 people were injured in the blast that took place in the early hours of May 12.

"We have got an order by the MHA (ministry of home affairs) to probe the case," NIA Deputy Inspector General Anurag Tankha told IANS.

"The process of handing over all documents concerning the probe by the state police has begun and the NIA is expected to formally begin the probe within 10 days," added Tankha.

While the state police claimed the explosion to be a result of gang war, the Bharatiya Janata Party (BJP) has been calling for a credible probe, accusing the Mamata Banerjee government of repeatedly covering up incidents of blasts and explosions occurring in the state.

Claiming that the train explosion had a terror link much like the October 2 Burdwan blast, the BJP has been demanding a central agency probe.

"Much like the Burdwan blast, the state government is trying to cover up this incident as well. I think the time has come that a credible investigation needs to be done and I hope the centre considers this," BJP national secretary Siddharth Nath Singh said after the explosion.