NEW DELHI, Feb 22: Indian police teams have fanned out to three northern states after blasts which killed 68 people on a train to Pakistan, detaining seven people for questioning, officials and a report said on Thursday.

Rajiv Dalal, police chief of Haryana -- where the attack took place -- told the Press Trust of India (PTI) news agency that the seven people were picked up in Rajasthan and other states.

“Interrogation in the case is on the right track,” Dalal told PTI.

One of the detainees resembled the police sketch of a suspect made public on Tuesday, PTI said.

Earlier, senior police official R.C. Mishra, who heads a special team leading the probe, told AFP that teams of investigators had been sent to “Bikaner (Rajasthan state) and Delhi, Uttar Pradesh.” “Some of the passport holders on the train had passports giving their address in that place,” he said.

Those passengers boarded the train, but were not on the list of people who reached Pakistan and were not among the victims, he said.

Indian police on Wednesday released a Pakistani national who had been travelling on the train, the Times of India said.

“He was taken to Delhi the night after the blasts, after which it was ascertained that he had no role in the explosions,” a senior police official said.—AFP