At least 27 passengers including seven women were injured when eight coaches of the Delhi-bound Ferozpur-Mumbai train derailed in Haryana's Rohtak district early on Sunday morning.
The Punjab Mail, which was on its way to Mumbai, derailed near Sampla-Kharawar at 3.50 am, Alok Mittal, inspector general of police of the Rohtak Range, said.
The accident site is over 70 km from Delhi.
Six bogies of the second-class sleeper compartment (S-5 to S-10), one luggage compartment and the guard coach jumped tracks, railway officials said, adding that five of the coaches overturned after the derailment.
Three passengers received grievous injuries in the incident while 24 others escaped with minor ones. All the injured passengers were shifted to a hospital at Rohtak.
Commissioner of Railway Safety, Northern Circle, R K Kardam will hold a statutory inquiry into the accident.
Preliminary information indicates that the derailment has been caused prima facie because of rail fracture.
Railway officials said that at least 50 metres of the rail track was found broken at the accident site.
"We are trying to ascertain whether the railway track broke due to the accident or whether the broken track led to the accident," a railway official said.
"Most of the passengers in the derailed coaches were sleeping when the accident took place," said police officials.
Thirty trains, including 16 local ones, were affected. They were cancelled or diverted.
A team of senior railway officials headed by Additional General Manager B P Gupta and Divisional Railways Manager, Delhi, Ashwani Lohani immediately rushed to the site of incident.
"After boarding the train, I fell asleep. A few hours later, all of a sudden I felt a severe jolt and fell from my berth," said Harjinder Singh.
"I broke my right hand. When I turned around, I could see that passengers had fallen on top of one other. It was a horrific scene, but luckily, we got timely help. Ambulances reached the site and we were extricated from the train," he said.