Ten people are in hospital - nine believed to have life-threatening injuries - after a stabbing attack on board a Doncaster-London King's Cross train on Saturday
Two people have been arrested after the train made an unscheduled stop at Huntingdon station, where dozens of officers rushed to help
British Transport Police say counter-terrorism officers are supporting the investigation as they "work to establish the full circumstances and motivation"
An eyewitness tells the BBC they saw a man with a bloodied arm fleeing down a carriage yelling "they've got a knife" - another witness says police Tasered a man on a platform
Prime Minister Keir Starmer says the "appalling incident" is "deeply concerning" and urges people to follow the advice of local authorities
Eyewitness tells BBC a man, with blood on his arm, shouted "someone's got a knife"
Emergency services rush to scene of Cambridgeshire train incident
BBC Verify has authenticated a video of the aftermath of the stabbing incident near Huntingdon.
The video, filmed on a bridge on Brampton Road overlooking Huntingdon's railway station, shows a stationary train while a number of police officers run down the platform.
We've just received a statement from Cambridge Police, who confirm that at 19:39 local time they received reports that multiple people had been stabbed on a train.
"Armed officers attended and the train was stopped at Huntingdon, where two men were arrested. A number of people have been taken to hospital," the statement says.
"The incident remains ongoing, and the A1307 has been closed as you approach the town centre."
We're now hearing from Conservative party leader Kemi Badenoch, who says in a post on X she is "deeply disturbed by the reports emerging from Huntingdon".
Quote MessageThis is an absolutely horrific attack and my thoughts are with all those affected including the emergency responders at the scene."
Kemi Badenoch, Conservative party leader
LNER has urged passengers to cancel or defer travel where they can, but says a limited number of services are running for those who were already travelling.
Passengers are able to use their tickets on the following services without incurring extra cost.
LNER notes that other services are likely to be busy, and they are working to get trains moving again "as quickly as possible".
Pictures are now coming in of the scene at Huntingdon, Cambridgeshire, where police are responding to reports of multiple people being stabbed on a train.
Image source, TikTok/@qonquest
Image source, TikTok/@qonquest
Jake Lapham
Live reporter
If you're just joining us, we're bringing you live updates as police respond to a stabbing incident in Cambridgeshire.
Here's what we know so far:
Here's what we don't know
This is a quickly developing situation - stay with us as we work to bring you the latest.
Home Secretary Shabana Mahmood has just posted on X, saying she is "deeply saddened to hear about the stabbings".
Quote MessageMy thoughts go out to all those affected. Two suspects have been immediately arrested and taken into custody. I am receiving regular updates on the investigation. I urge people to avoid comment and speculation at this early stage."
Shabana Mahmood, Home Secretary
James Hore
BBC News
We've just received a statement from a spokesperson for the East of England Ambulance Service.
They confirm that they received a call at 19:39 GMT to reports that "multiple people had been stabbed on a train".
“We mobilised a large-scale response to Huntingdon Railway Station which included numerous ambulances, tactical commanders, our Hazardous Area Response Team and critical care teams including the East Anglian Air Ambulance and Essex and Herts Air Ambulance.
“We can confirm we have transported multiple patients to hospital. Further updates will be issued by British Transport Police.”
Paul Bristow, the mayor of Cambridgeshire and Peterborough, says in a post on X: "Hearing reports of horrendous scenes on a train in Huntingdon, Cambridgeshire.
"Cambridgeshire Police are at the scene and two people have been arrested."
We're now hearing from the prime minister, who describes tonight's incident as "deeply concerning".
"The appalling incident on a train near Huntingdon is deeply concerning," Keir Starmer says in a post on X.
Quote MessageMy thoughts are with all those affected, and my thanks go to the emergency services for their response. Anyone in the area should follow the advice of the police."
Prime Minister Keir Starmer
Local authorities say this incident occurred on a train that was stopped in Huntingdon, Cambridgeshire, however it's unclear if that was its final destination.
Cambridgeshire is about 50 miles (80km) north of London.
Part of the East of England region, it also takes in areas like Cambridge and Peterborough.
The general secretary of the transport union, the National Union of Rail, Maritime and Transport Workers (RMT) says he's "deeply concerned to hear reports of multiple people stabbed onboard an LNER train tonight".
Eddie Dempsey says "the thoughts of everyone at RMT are with the victims, train crew and all the emergency services dealing with this unfolding incident".
LNER, which operates East Coast Mainline services in the UK, is urging passengers not to travel because of "major disruption" caused by the multiple stabbings on a train to Huntingdon in Cambridgeshire.
In a statement on X, the company writes: "We are experiencing major disruption across the LNER route."
"Emergency services are dealing with an incident at Huntingdon station, all lines are blocked."
"Our advice is 'Do Not Travel'. Please defer your travel where you can."
Two people have been arrested after "multiple people" were stabbed on a train to Cambridgeshire.
British Transport Police are currently responding to the incident on an LNER train to Huntingdon.
Armed officers attended the scene and two men were arrested following 999 calls at 19:39 GMT.
More than 30 officers were sent to the scene. No details about how many people have been stabbed have been released, or how serious the injuries are.
We're still gathering details on what has happened, stay with us as we bring you the latest updates.