Activists of a Pakistani religious party burn an Indian flag at a rally Monday in Multan, Pakistan, to condemn a deadly train attack in India. A pair of explosions on a train headed for Pakistan set off a fire that killed at least 66 people.

Dewana, India ? Leaders of India and Pakistan pressed ahead Monday with their peace process, hours after twin bombs – apparently intended to disrupt their relations – sparked a fire that killed 66 people aboard a train that links the two rivals.

The fire destroyed two coaches on the Samjhauta Express, about an hour after the train left New Delhi on its way to the Pakistan border. Officials said the attack was timed ahead of the arrival of Pakistani Foreign Minister Khursheed Kasuri, who was expected today in the Indian capital.

“This is an attempt to derail the improving relationship between India and Pakistan,” Railway Minister Laloo Prasad told reporters.

Pakistan quickly decried the attack, and Indian officials took pains to avoid laying any quick blame. Each side appeared to reach out across the border.

Indian Prime Minister Manmohan Singh declared his country’s “abhorrence for this heinous terrorist act,” and expressed his condolences by telephone to Pakistani Prime Minister Shaukat Aziz, according to Singh’s office. Most of the dead were Pakistani.

India will do “everything possible to ensure that its perpetrators are punished,” the statement said.

A Home Ministry official, speaking on condition of anonymity because of the investigation, said no suspects had been ruled out – from Kashmiri separatists to Hindu extremists.

Speaking to India’s CNN-IBN television, Kasuri called the bombing a “terrible act of terrorism” and said “the peace process must go on with greater vigor and greater determination.”

Navtej Sarna, spokesman for India’s foreign ministry, read a statement that focused, in large part, on help being offered by India to Pakistani families.

“The entire process is being carried out in cooperation with Pakistani authorities,” he said, adding that Pakistani diplomats were visiting the scene and that visas would be issued quickly for Pakistani relatives of the dead and injured.

“We will not allow elements which want to sabotage the ongoing peace process and succeed in their nefarious designs,” Pakistani President Gen. Pervez Musharraf was quoted as saying by state-run Associated Press of Pakistan.

India’s junior home minister said the bombs were intended only to start a fire and were timed to explode ahead of Kasuri’s arrival today.

United Nations Secretary-General Ban Ki-moon condemned the bombing and said he was satisfied the leaders of India and Pakistan were determined to continue their dialogue.

Authorities say two suitcases packed with crude unexploded bombs and bottles of gasoline were found in undamaged train cars, indicating the fire had been sparked by similar devices.

Witnesses described a horrific scene as the train stopped on an isolated stretch of railway near the village of Dewana, about 50 miles north of New Delhi. The train’s driver apparently didn’t realize what was happening in the seconds after the blasts, until the assistant station manager in Dewana saw fire shooting from the cars as they sped past.