There were also over 50 injured when two bogies of the Samjhauta Express, from Delhi to Pakistan border, caught fire after a series of explosions on Sunday night, the Indian Catholic reports.
Indian officials believe it was a terrorist plot, and fear that the number of dead could further climb.
Samjhauta Express, which runs between Old Delhi railway station and Attari, the last Indian railway station in Punjab at the border with Pakistan, reflects the state of Indo-Pak relations.
It has been cancelled when the bilateral tensions mounted, and its bi-weekly chugging from the Indian Capital to the border symbolises the thaw in relations between the two nuclear powers.
The fire broke out when the train, which had several Pakistani citizens, was in Shiva Village in Panipat district, about 100-kilometres from Delhi.
Police officials recovered at least two explosives close to the site of fire. Sources in the Indian security establishment believe it could be the work of a terror group bend upon destroying the ongoing Indo-Pak efforts at peace.
The attack came a day ahead of Pakistan foreign minister Mohammed Kasuri's visit to New Delhi for chairing the Indo-Pak Joint Commission which reviews all aspects of the bilateral ties.
Speaking to AsiaNews, Indian Bishops Conference President, Cardinal Telesphore Toppo said the train service "was a symbol of the growing peace and harmony between India and Pakistan".
"Sadly, there are those who want to disrupt the friendship that is being built between the two countries and that is a cause for concern. India, just seven months ago, was a target of a series of deadly attacks, and now she weeps for this new tragedy," he said.
He expressed his "deepest sympathy and closeness to those who are mourning the loss of their loved ones, victims of this act of terror."
The Indian Church through its parishes and mission stations," he said, "extends every support to the victims and their families. We want to help survivors, materially and spiritually."
"Yesterday," Cardinal Toppo concluded, "the Church proclaimed that the enemy must be loved. This is the teaching of the Scriptures and this is what we reaffirm: Pray that the divine light might illuminate this moment of darkness."
Train attack, a "most inhuman tragedy," says Cardinal Toppo (AsiaNews, 19/2/07)
Terror in peace train: 64 dead, 50 injured (Indian Catholic, 19/2/07)
LINKS (not necessarily endorsed by Church Resources)
Catholic Bishops' Conference of India
Samjhauta Express (Wikipedia)
Indian Catholics mark Gandhi non-violence centenary (CathNews, 6/2/07)
20 Feb 2007