The attack occurred on the 18:25 GMT London North Eastern Railway (LNER) service from Doncaster to London King’s Cross. The train involved was number 800111 and the headcode was 1Y90. Passengers reported that at least one person armed with a knife began attacking people after the train passed through Peterborough in Cambridgeshire. Police were alerted at around 19:40 by calls from those on board.

The train made an emergency stop at Huntingdon, approximately 15 minutes from Peterborough, where armed officers boarded and arrested two individuals. A major emergency response was deployed, including air ambulance units. The incident is estimated to have lasted between 10 and 15 minutes. Passengers who were not injured were interviewed by police before some were transported to London by coach.

Huntingdon MP Ben Obese-Jecty said there were “about 10 ambulances, several fire engines and well over 20 police cars” when he arrived shortly after 21:00. On Sunday morning, Huntingdon station remained closed along with the A1307 directly outside. The train involved remained at the platform, with police officers and forensic tents still present.

Emergency services transported 10 people from the scene, with police stating that nine are believed to have suffered life-threatening injuries. None of the victims have yet been formally identified. They were taken to Addenbrooke's Hospital in Cambridge, around 30 minutes from Huntingdon station.

Passengers described panic inside the train as people ran through carriages seeking safety, some visibly injured and covered in blood. Witnesses told the BBC they initially had little idea what was unfolding, with confusion spreading as the attack began.

Olly Foster reported hearing passengers shouting "run, there's a guy stabbing literally everyone and everything", initially believing it might be a Halloween prank. He described seeing an older man with cuts to his head and neck after he “blocked” the attacker from harming a younger girl, with fellow passengers using jackets to stem the bleeding.

Another witness, Wren Chambers, said one victim had been stabbed in the arm and ran down the train to warn others, while another shouted "someone's got a knife". Some passengers hid in toilets, while others rushed towards the front of the service in search of safety.

London Underground worker Dean McFarlane said he saw several people running along the platform at Huntingdon covered in blood, including one man in a white shirt who was “completely covered in blood”.

British Transport Police (BTP) declared a major incident following the attack and confirmed that counter-terrorism officers were assisting to “establish the full circumstances and motivation for this incident”. The force later confirmed it had briefly declared “Plato” — the emergency services’ national protocol for responding to a “marauding terror attack” — before standing it down.

Ch Supt Chris Casey said: “We're conducting urgent enquiries to establish what has happened, and it could take some time before we are in a position to confirm anything further. At this early stage it would not be appropriate to speculate on the causes of the incident.”

Defence Secretary John Healey told the BBC that early information suggested the incident was isolated. Asked whether it was terror-related, he said the investigation remained ongoing and that police would “let us know as much as they can as soon as they can”. Healey noted he frequently uses the same train service, and had travelled the route only hours before the attack, while praising the emergency services for their response.

Prime Minister Sir Keir Starmer described the incident near Huntingdon as “deeply concerning”. On X he said: “My thoughts are with all those affected, and my thanks go to the emergency services for their response.”

Home Secretary Shabana Mahmood said she was receiving regular updates on the investigation and urged the public to “avoid comment and speculation at this early stage”.

Conservative leader Kemi Badenoch said she was “deeply disturbed by the reports emerging from Huntingdon”. She added: “This is an absolutely horrific attack and my thoughts are with all those affected including the emergency responders at the scene.”

Trains are now starting to run between the affected area but there will understandably be potential cancellations and delays. LNER currently offer the following advice to passengers:

• Customers travelling today, Sunday 2nd November are advised to check before they travel, as there may be cancellations or alterations to the services today. LNER services are running to and from London Kings Cross today.

• LNER tickets dated Saturday 1 November and Sunday 2 November are valid for travel up to and including Friday 7 November. You don’t need to change or amend your existing ticket, but they do recommend making a seat reservation before you travel.

• If you are due to travel on Sunday 2 November, it is recommended to check for the latest updates before you set off. If you no longer wish to travel, you are entitled to a full refund of any unused tickets dated up to Friday 7 November from the original point of purchase. For tickets purchased via the LNER website, a refund can be requested via your account.