The fire started in the restroom of one car in the Golden Temple Express and spread quickly to two others, a railroad official said on condition of anonymity.
The spreading flames jammed the doors, trapping passengers as the train headed to the northern city of Amritsar from Bombay, police officer Amandeep Singh said. Police found 34 of the bodies in one car.
The Press Trust of India news agency reported that authorities saw no signs of sabotage to the train. They believe the fire might have been started by a spark from a short circuit or spilled flammable liquid carried by a passenger.
Most of India's worst train tragedies are caused by poor maintenance, although there have been cases of sabotage to train tracks by separatist rebels. In 1998, the same Golden Temple Express rammed into three derailed cars of another train, killing more than 200 passengers.
In Thursday's fire, the train stopped as panicked passengers pulled the emergency chains. The burning cars were detached at Ladhowal railroad station, nearly 195 miles north of New Delhi. The rest of the train later continued on to Amritsar.
Harpal Singh, a businessman from New Delhi, survived but his friend Paramjit Singh perished in the fire.
``I was awakened by the shouts of passengers and found my way to another coach using the vestibule,'' Singh said.
``Passengers pulled the chain to stop the train after they noticed the fire. They jumped off as the train slowed down and came to a halt,'' he said.
Rescuers and local villagers took nearly three hours to extinguish the flames, police said.
The injured were hospitalized in the nearby city of Ludhiana in Punjab state, where relatives began arriving to get word of their loved ones.
``We were all sleeping at the time,'' said Padma Wati, who was traveling to Amritsar to pray at the Golden Temple, the holiest shrine for Sikhs in India, with her two teenage children and sister.
Wati said she awoke around 4 a.m. when she heard others rushing toward the windows and banging on doors. She jumped from a door with her family, but could not find her children at the Ludhiana hospital, where she was being treated for scratches.
