The accident occurred around 5.45 pm near Khatauli town, 40 km off Muzaffarnagar, leaving 23 people dead, the Uttar Pradesh Police said.
Deepak Agarwal, Commissioner, Saharanpur Divison and District Magistrate, Muzaffarnagar, G S Priyadarshi said the official figure of bodies in the mortuary was 21, while another body, of a woman, was being pulled out.
Railway ministry officials in Delhi, however, put the number of dead at 12 and the injured around 75.
Priyadarshi said 90 people were injured in the accident and most of them have been admitted at district hospital, Muzaffragnagar.
More From This Section
Some others were taken to Muzaffarnagar Medical College and Meerut Medical College, he added.
District authorities have also issued three helpline numbers: 0131-2436103/2436918/2436564
NDRF officials said the search and rescue operations were "practically over" at the accident site with the last of the bodies presumably being pulled out from the wreckage of the coaches.
The train was coming from Puri in Odisha and going to Haridwar in Uttarakhand, normally a journey of about 36 hours.
Heavyweight cranes and gas cutters were being used to lift or cut the mangled remains of the coaches and extricate passengers stuck inside.
Large number of local people and villagers were also seen helping out those engaged in the rescue work.
Policemen on the site said one of the derailed coaches had crashed into the wall of a house adjacent to the railway track and some people are feared to be trapped in the debris.
When asked by a reporter whether there was any terror angle in the accident, state DGP Sulkhan Singh said so far there was no such information, but "UP ATS will investigate into the causes of the accident."
The coaches damaged were S1 to S10 sleeper class, third AC B1, second AC A1 coach and the pantry.
Muzaffarnagar authorities have set up a control room to assist families of those affected. The numbers are: 0131- 2436918, 0131-2436103 and 0131-2436564.
He said the situation was being monitored very closely by the Railways Ministry.
At least 10 passenger trains on the busy route were diverted following the accident, a Northern Railway release said.
Railway Minister Suresh Prabhu ordered an inquiry into the derailment. He said he was personally monitoring the situation and strict action will be taken in case of any lapse.
Prabhu also announced Rs 3.5 lakh ex-gratia compensation for those who lost their lives, Rs 50,000 for the seriously injured and Rs 25,000 for those who received minor injuries.
In a series of tweets, Prabhu said Minister of State Manoj Sinha has rushed to the spot while the Chairman of Railway Board and Member Traffic have been asked to oversee rescue and relief operations.
"Rescue operations have been completed. All injured shifted to hospital. Restoration work will start now. Still monitoring situation closely.
"Have directed Railway Doctors to visit the injured in hospitals and ensure best possible medical help.
NDRF DG Sanjay Kumar said the rescue operations began at 8.50 pm and four teams were pressed into service. "Bodies of two males and a woman were extricated from beneath the mangled remains, while efforts were on to pull out another woman's body," he said in Khatauli.
The DG said the National Disaster Response Force (NDRF) personnel were trying to bring back to the ground one of the coaches which had settled atop the other due to the impact of the crash, adding, "So technically the operation would be over once we put the coach back on ground."
Another senior NDRF official at the accident site said, "About 165 personnel, including dog-trainers, worked on the rescue operations."
Medical vans were also rushed to the site.
The Railway ministry was also in close touch with the Uttar Pradesh government to coordinate rescue and relief operations.
In Lucknow, Uttar Pradesh ADG (Law and Order) Anand Kumar said that top priority was being accorded to ensure prompt rescue and relief work.
Meanwhile, Railways spokesperson Anil Saxena said, "Initially, we thought that it was only 4-5 coaches, now we have ascertained that 14 coaches have derailed. As of now our focus is on rescue and not on finding reasons for the accident."
Kumar also said IMA chapters in Meerut zone have been alerted and asked to ensure adequate and prompt medical care to the injured.
Uttar Pradesh Chief Minister Yogi Adityanath enquired about the accident and directed officials to take all possible action, an official spokesperson said.
UP ministers Suresh Rana and Satish Mahana visited the accident site and took stock of the situation after chief minister Adityanath directed them to reach Khatauli to expedite rescue and relief operations.
According to a statement from railway ministry, the 14521/14522 Ambala-Delhi-Ambala Intercity Express, 18478 Haridwar-Puri Utkal Kalinga Express and the 14682 Jalandhar- New Delhi Intercity Express, which will commence journey tomorrow, stood cancelled.
Manoj Baliyan, a local resident, said he heard a massive thud and the next thing he saw was a blue railway coach flying over another coach and hit his house like a giant projectile.
When the 42-year-old man gathered his wits all he could see was scores of bodies in front of the house, along the railway track.
"A coach had even rammed the boundary wall of a college building near our house," said Baliyan, who runs a shop in the area.
"There was a massive thud and one of the coaches flew over the pantry car and rammed our house's porch," he told PTI.
The other end of the S2 coach is resting over the pantry coach with its doors shattered.