A train driver has died and 89 people have been injured after two trains collided in the Bedford area as police declare a major incident.
Eleven people suffered very serious injuries, 22 were seriously injured and a further 56 have minor injuries, the East of England Ambulance service said.
The crash involved two southbound East Midlands Railway (EMR) services, both travelling to London St Pancras on Friday afternoon. The cause of the incident is still under investigation.
RMT general secretary Eddie Dempsey said the union was "devastated to learn that a train driver and former RMT rep has tragically died" in the crash.
In a statement, the British Transport Police (BTP) said they had declared a major incident following the collision, which took place at around 17:15BST.
"We know that a number of people have been injured and one person has very sadly died", the statement said.
East Midlands Railway services to and from London St Pancreas were suspended for the rest of Friday evening and disruption is expected into Saturday.
Passenger Dr Peter Knapp told the BBC he was travelling in the "front carriage of the train that collided into another one".
"When I got up, I saw all of the chairs everywhere. It felt like I'd been in a bomb explosion.
"When I got up, I saw people's bloodied faces and people's legs looked broken and there was smoke everywhere", he said.
Speaking from the side of the road, Knapp said the police were taking passengers details while some were taken taken to hospital. "Some people are spitting out blood", he said.
Shola Mene, another passenger on one of the trains involved, said she heard a "big bang", adding: "People flew from their seats, the seats were pulling, and then someone just flew across and hit my husband in the face.
"There was a lot of blood. A lot of people had facial injuries", she said.
After the collision, there was a lot of confusion about what had happened, Mene said.
Transport Secretary Heidi Alexander said she was "deeply concerned" by the news of the collision, and the death of one person.
"My thoughts are with all of those affected," she told the media on Friday evening, "especially the people who've been injured, their friends and their family".
When asked about the cause of the fatal incident, Alexander said that it was "too early to speculate".
"We will make sure that there's a thorough investigation done to establish how this collision happened and to ensure that lessons are learned so that we don't have an incident like this ever again," Alexander said.
"The UK railways are some of the safest in the world," she added. "It's very unusual for this to happen on the network."
An air ambulance was dispatched as part of the emergency response to the collision, which happened just south of Elstow, near the the road interchange of the A421 and A6.
Aerial footage of the aftermath shows the two damaged trains with most carriages on the tracks but at least one shunted off.
The two trains involved were the 16:40 EMR train from Corby to London St Pancras and the 15:50 Nottingham at London St Pancras at Bedford South, an EMR spokesperson said.
Teresa Itabor, from Wellingborough in Northamptonshire, told the BBC she got on the train at 16:57 at Wellingborough and was heading to the capital to celebrate her birthday.
"We left Bedford station and there was a massive bang... I didn't know what was going on. My head hit the seat in front of me," she said.
"I opened my eyes and that's when I saw people on the floor with blood everywhere."
A spokesperson for the National Union of Rail, Maritime and Transport Workers said: "We are deeply concerned by reports of a train collision between Bedford and Luton and the serious injuries sustained by on-board train staff and passengers.
"The thoughts of the whole union are with those affected and we continue to monitor the situation."
EMR has advised travellers to use alternative routes for services to and from London St Pancreas until the end of the day on Saturday 20 June.
Tickets can be used at no extra cost to travel on the alternative routes, EMR said, adding that other train operators are aware of the "disruption to your journey ".
