"I have been told by railway officials that 15 to 20 people have died," Railway Minister Lalu Prasad Yadav said in New Delhi on Tuesday.
Later reports said the toll could be as high as 50.
Indian news agencies and media reported that dozens had been hurt in the crash. "The cause of the accident is not known," Yadav added before leaving for the crash site near Mansar village, 150km east of the holy Sikh city of Amritsar in Punjab state.
Mulkha Raj Sharma, station superintendent in the city of Jammu, the winter capital of Indian Kashmir, said the trains had collided head-on.
Army called in
The army was called out to help in the rescue efforts and cranes had arrived at the crash site near Mansar, witnesses said. Villagers near the scene in the heart of rural India helped in frantic efforts to free trapped passengers.
One of the trains involved in the collision was an express train
"The cause of the accident is not known"
Lalu Prasad Yadav,
which left Jammu on Tuesday morning bound for the central Indian city of Bhopal, Sharma said, adding relatives and friends of passengers aboard the Jammu train had rushed to the station for word about the fate of their loved ones.
The other train involved was a local one, the railway minister said.
India's railway system, which stretches 108,700km across the nation of more than a billion people, suffers accidents on a nearly daily basis owing in part to its antiquated infrastructure.
In September 2002, 130 people died when the luxury Rajdhani
Express plunged off a bridge and tumbled into a river in eastern India.