Pakistan on Monday condemned the deadly blasts on the Delhi-Attari train as an act of terrorism.
"We condemn this act of terrorism in which many precious lives have been lost. We deeply sympathise with the families of the victims who lost their lives," Pakistan Foreign Office Spokesperson Tasnim Aslam said.
She said preliminary reports indicated that many of those who lost their lives were Pakistanis.
Aslam said it is the responsibility of the Indian government to provide security for the train. "We expect the Indian government to conduct investigation into the incident and punish those responsible for this," she said.
Asked whether the incident would have any affect on the proposed visit of Pakistan Foreign Minister Khurshid M Kasuri to New Delhi on Tuesday, Aslam said, "We do not want to prejudge the investigations. We expect India to conduct investigations and the Pakistan high commission officials have been asked to visit the spot to help the victims and send a report."
66 people, including Pakistanis, were killed in an explosion on the special train in Deewana near Panipat.
Pakistan's Railway Minister Sheikh Rashid Ahmed said emergency has been declared in Lahore to receive the injured and to arrange treatment for them and efforts were on to bring the bodies of those killed in the bomb explosions to Lahore by a special train.
"We are waiting for a word from Indian officials to arrange for the train," he said.
The local railways have set up special counters and telephone numbers for the relatives to obtain information.
Asked whether the explosions were caused due to a security breach, he said special security was accorded to the train on both sides and the train does not stop anywhere after it leaves New Delhi.
"The government will wait for the results of the Indian government's investigations," he said.
The Indian high commission in Islamabad, meanwhile, announced that visas would be provided immediately to the relatives of the victims of the bomb attack on the train to visit India.
A senior Indian official said the decision to grant visas were being announced through the local TV channels.