Two bombs on a train travelling from India to Pakistan caused a fire in which at least 66 people were burned alive. Officials said the attack was an attempt to disrupt the peace process between the two countries.

The blasts, which occurred at midnight on Sunday outside the village of Sewah, 50 miles north of Delhi, saw flames leap into the sky and caused distraught passengers to jump from one of the two burning coaches.

Witnesses said the fire in the other coach was so intense that its occupants could not open the doors. Two victims died beside the tracks.

Kailash Sharma, a 32-year-old local resident, said he saw a fireball and heard screaming. He said he was among 30 villagers who rushed out with buckets of water. "We could not put the fire out ... it was so hot and a shock for us. The fire engines took two hours to put out the flames."

Authorities said two suitcases packed with crude unexploded bombs and bottles of gasoline were found in train cars not affected in the attack, indicating the fire was sparked by an identical explosive device. "These were low-intensity devices whose purpose was to cause fire and burn people alive," said VN Mathur, general manager of the Northern railway.

Crash investigators were poring over the blasted coaches yesterday morning. The blue paint of the carriages had been peeled off by the heat and inside little was left apart from the charred skeletal remains of seats and luggage racks.

Relations between India and Pakistan have been improving since the two countries came close to war in 2002. Pakistan's foreign minister, Khurshid Ahmed Kasuri, will arrive in New Delhi today for talks on the peace process.

Analysts said it was likely the attack was orchestrated by militant Islamist groups, concerned that warmer ties between India and Pakistan may see the two cut a deal on the disputed territory of Kashmir without considering them.

Kuldeep Nayar, a veteran analyst with contacts in both establishments, said: "That is a factor especially in Pakistan. It says you cannot do [peace] without us. It is an indirect impact on the peace process."

Early yesterday the charred remains of the victims, most of whom were Pakistani, were being taken to hospital in Panipat. The survivors who were said to be in a critical condition were rushed to Delhi.

At Panipat hospital relatives of the dead milled around the three dozen coffins stacked beside the morgue. Inside a dazed Muhammad Fayaz, 29, wandered around the morgue clutching the platform ticket he used to see his mother, Shokeena Begum, off from Delhi.

"She was going to see my cousins in Pakistan. Now she will never come back," he said.

The service, called the Samjhauta, or Compromise, Express, was meant to reunite families divided by Indian-Pakistani animosity. When the train restarted in 2004 it symbolised closer links between the estranged countries.

Officials on both sides said the train service would resume, with beefed up security. Relatives had complained that lax checks in Delhi railway station were to blame.

Laloo Prasad Yadav, the Indian railway minister, touring the burned out carriages, called the bombing an "act of sabotage ... to derail the improving relationship between India and Pakistan".

The Pakistani president General Pervez Musharraf, said: "We will not allow elements which want to sabotage the ongoing peace process to succeed in their nefarious designs."