At least 8 persons were killed and around 60 injured in a powerful explosion, triggered by suspected extremists in the general compartment of a passenger train when it halted at Belakhoba station in West Bengal's Jalpaiguri district on Monday evening.

Inspector General of Police (Railways) Tushar Bhattacharya told PTI in Kolkata that 8 persons were killed in the explosion that took place in Haldibari-Siliguri passenger train at 6:30 pm. The explosion was so severe that a side and the roof of the bogie were blown away.

IGP (Law and Order) Raj Kanoria said the bodies were charred beyond recognition.

The toll might go up as several of the injured were in a critical condition in hospital, Bhattacharya said.

Home Secretary P R Roy said the explosion was suspected to be the handiwork of North Bengal militants.

Asked if he suspected the militant group Kamtapur Liberation Organisation, which has links with United Liberation Front of Assam, he said: "It might be the KLO or the ULFA. We are trying to get details."

Eyewitnesses said there was a flash followed by a deafening explosion. There were two small explosions immediately afterwards.

"Some of the passengers jumped out of the coach in panic, while many received burns," they said.

No militant group has so far claimed responsibility for the blast.