NEW DELHI, Feb 21: Indian investigators are looking into a suspicious phone call made to Azad Kashmir just after bombs on a train bound for Pakistan killed 68 people, an official said on Wednesday. But Kashmiri militants denied any role.

The governments of both India and Pakistan have blamed the firebomb attack on extremists trying to undermine the peace process between the nuclear-armed rivals.

Even though most of the victims were Pakistani, the Indian police say Islamic extremists are prime suspects.

And intelligence agencies seem to think that a phone call from Delhi to Azad Kashmir just after the attack could provide an important lead.The Times of India newspaper quoted a home ministry official on Wednesday as saying the call had been recorded and could hold “the key to the entire puzzle”.

“Yes, a call was made and it is a vital link,” an official from India’s Intelligence Bureau, told Reuters.

On Tuesday, the Indian police released sketches of two suspects who are believed to have jumped from the train just before two suitcase bombs packed with fuel sparked the deadly fire.

On Wednesday, the focus of the investigation moved to the teeming streets of Old Delhi. Police believe the suitcases could have been bought there before being loaded on the train, and said they were questioning shopkeepers.

“We are also examining the video recordings of the close-circuit television at the Old Delhi railway station, though the visuals are not of a good quality,” a senior police officer said.

In the state of Haryana where the bombs exploded, senior police inspector R. C. Mishra said his team was trying to find out which militant group could have been behind the attack but had not yet pinned anything down.

In Kashmir, militants vehemently denied any role.

“We strongly condemn the attack on innocent people,” the United Jihad Council said in a statement.

“Our fight is against the Indian government and not against innocent civilians,” it said. “Our target is Indian security forces and our aim is liberation.” Suspicion in India after such attacks usually falls on Lashkar-i-Tayyaba, which is not part of the mainly Kashmiri UJC and is seen as promoting a more hardline agenda.

But a caller identifying himself as Abdullah Gaznavi, a spokesman for Lashkar, told Reuters in Kashmir that his group was not responsible.

“The claims by Indian police that Mujahideen are behind the blasts is malicious propaganda aimed at maligning the image of Mujahideen,” he said.—Agencies