More than 100 people were killed and around 150 injured when 14 coaches of the Indore-Patna Express derailed near the city of Kanpur before dawn on Sunday, officials said.
The horrific disaster took place when the Patna-bound train's coaches ran off the rails just after 3 a.m. near Pukhrayan station, about 60 km from Kanpur city, railway and police officials said.
Uttar Pradesh Inspector General of Police Prabhakar Chowdhary told IANS that the number of dead had crossed the 100 mark and that the toll could rise further considerably.
The passengers were asleep when the disaster struck, taking everyone unawares. The first to derail were the S1 and S2 coaches, which suffered the maximum damage.
Most of the dead were crushed to death, an official of the National Disaster Response Force (NDRF) told IANS. Some of the injured were in critical condition.
NDRF spokesperson Krishna Kumar said: "Most bodies which have been taken out are beyond recognition as they are badly crushed."
A passenger who survived told journalists that the train stopped a couple of moments after 3 am for unexplained reasons.
"It then suddenly picked up speed," the man said. "And then I got an eerie feeling that the train was rolling down a valley. By the time I realized what had happened, some 20-25 people in my coach had been killed. There was a six-year-old girl who was literally cut into two pieces," said the terrified man.
It was the worst train accident in the country after the May 2010 disaster in West Bengal involving Gyaneshwari Express that killed some 170 people.
"We were sleeping and the train suddenly derailed," said Ruby Gupta, who was going from Indore to Mhow to attend a wedding. "My father is nowhere to be seen since then. Some people are telling me to look for him in the hospital. I just need my father back."
Said another dazed survivor: "I was awake when the train derailed. There was a loud noise and then pandemonium broke out. I thought I was dreaming. My wife and children are fortunately safe... We are very sacred."
Survivors said the first to reach the semi-rural site were villagers. The government's rescue and relief teams came after day broke.
Prime Minister Narendra Modi and a host of VIPs mourned the deaths. Modi announced ex gratia of Rs 2 lakh for the next of kin of those killed and Rs. 50,000 for the seriously injured.
Railway Minister Suresh Prabhu and the Chief Ministers of Uttar Pradesh and Madhya Pradesh, where the train originated, also announced financial compensation to the dead and the injured.
Soldiers and NDRF teams frantically cut through the mangled coaches to pull out bodies and the injured. Thousands of people crowded the site and tried to offer help.
The railways used heavy machinery to separate the coaches, some of which had rolled over one another.
Some passengers complained that there had been unexplained noises in the S1 coach but the train staff did not pay heed.
Prabhu ordered an inquiry, said necessary assistance was provided to the victims and vowed to take "strictest possible action" against the guilty.
Later, after noon, a special train left from the accident site for Patna with the passengers who survived the disaster.
"A high-level probe has already been ordered and we will take strict action. The engineers and experts will probe the cause of the accident, but it appears there was a rail fracture," Minister of State for Railways Manoj Sinha told media persons at the accident site.