The death toll following the derailment of a train in India's northern Uttar Pradesh state has now passed 100, with more than 150 injured, police say.
Fourteen carriages of the Indore-Patna Express derailed just after 03:00 local time on Sunday near the city of Kanpur.
Rescuers cut their way through the twisted carriages to retrieve bodies and rescue the injured.
It was not immediately clear what caused the coaches to derail.
Krishna Keshav, who was travelling on the train, told the BBC: "We woke with a jolt at around 3am. Several coaches were derailed, everybody was in shock. I saw several bodies and injured people."
Most of the victims were located in two carriages near the engine which overturned and were badly damaged, reports said.
Rescue workers at the site were using heavy machinery to cut through the carriages to reach survivors.
Indian prime minister Narendra Modi tweeted: "Anguished beyond words on the loss of lives due to the derailing of the Patna-Indore express. My thoughts are with the bereaved families.
"Prayers with those injured in the tragic train accident."
Mr Modi said he had spoken to Railways Minister Suresh Prabhu, who was "personally monitoring the situation closely".
On his own Twitter account, Mr Prabhu warned that "strictest possible action will be taken against those who could be responsible for accident".
He said an investigation into the crash would begin immediately and compensation would be paid to "unfortunate passengers who died and to injured".
Home Minister Rajnath Singh said that India's National Disaster Response Force was overseeing the rescue efforts.
Kanpur is a major railway junction and hundreds of trains pass through it every day.
Anil Saxena, a spokesman for the railway company, said trains were being diverted along other routes.
Train accidents are common in India, where much of the railway equipment is out of date. About 23 million passengers use the country's vast network every day.