Pukhrayan, India - Emergency workers raced Sunday to find any more survivors in the mangled wreckage of an Indian express train that derailed overnight, killing over 100 people, in the worst disaster to hit the country's ageing rail network in years.
Many were sleeping when 14 carriages leapt from the tracks in a remote area of Uttar Pradesh state, and shocked passengers recalled being jolted out of their slumber by a violent thud.
"I woke up suddenly around 3.10 am and felt a tremor. The train came to a screeching halt," survivor Yaqoob Ahmed told the Hindustan Times newspaper from a hospital in the nearby city of Kanpur.
"All of a sudden, I was crushed under a crowd of people... everyone was screaming for help." Survivors also told of their desperate search for loved-ones on the train, which was carrying at least one wedding party with the marriage season in India in full swing.
Hundreds of army and police have been deployed at the scene, where rescue workers used gas-powered metal cutters to slice through severely mangled coaches to try to get to survivors.
"We have been able to pull out 24 people, out of which five were found to be alive," said Brigadier A. Chhibbar, who is leading the army's rescue operations.
"We will carry on day and night, till there is any inkling of even a single person being pulled alive." Police said over 100 people had been killed and another 150 injured and rushed to nearby hospitals, which had been placed on high alert after the early morning disaster.
It is the worst disaster since 2010 when a passenger train crashed into a freight train in the eastern state of West Bengal, killing 146 and injuring over 200.
Authorities have launched an official investigation into the accident, which junior railways minister Manoj Sinha said may have been caused by damage to the tracks.
India's railway network, one of the world's largest, is still the main form of long-distance travel in the vast country, but it is poorly funded and deadly accidents occur relatively frequently.
A 2012 government report said almost 15,000 people were killed every year on India's railways, describing the deaths as an annual "massacre".
Nitika Trivedi, a student who boarded the train with her family, said images of the victims' bodies would long haunt her.
"I had never seen anything like this in my life before. I am shaken to the core," she said.
Anxious relatives thronged the station in Indore in central India where the train originated, many clutching pictures of their loved-ones, and railway officials said special trains had been deployed for stranded travellers.
"We are also trying to clear the tracks and complete the restoration work as quickly as possible," Vijay Kumar, a spokesman for north-central railways, told AFP.
Local media reports said the train was packed with families, some of them travelling home for weddings.
Bride-to-be Ruby Gupta, who survived the accident with a fractured arm, was desperately searching for her father.
"I have been looking everywhere for him," she told the Press Trust of India.
In 2014 an express train ploughed into a stationary freight train, also in Uttar Pradesh, killing 26 people.
And last year 27 people died when two trains derailed in Madhya Pradesh state during heavy rain.
Prime Minister Narendra Modi's government has pledged to invest US$137 billion (S$195 billion) over five years to modernise the crumbling railways, making them safer, faster and more efficient.
On Sunday Modi tweeted that he was "anguished beyond words" by the loss of life in the latest accident.