32-year-old suspect arrested in stabbing of multiple people on UK train: Police

A 32-year-old man has been arrested on suspicion of attempted murder for allegedly attacking multiple people with a knife aboard a train headed to London on Saturday evening, according to police, a crime the prime minister called an "appalling incident."

In a statement shortly after the attack, British Transport Police (BTP) said two people had been arrested. On Sunday afternoon, however, police said a 35-year-old London man initially taken into custody had been released after investigators determined he was not involved.

The victim who was most seriously injured in the attack is a member of the London North Eastern Railway (LNER) staff, who was stabbed when he intervened in an attempt to stop the attack.

Deputy Chief Constable Stuart Cundy of the BTP praised the railway staff member on Sunday afternoon for protecting other passengers, saying security video aboard the train captured the employee's courageous actions.

"Having viewed the CCTV from the train, the actions of the member of rail staff were nothing short of heroic and undoubtedly saved people's lives," Cundy said.

The LNER staffer remained hospitalized on Sunday evening in "life-threatening condition," according to the BTP. Five other people who were hospitalized with stabbing injuries have been treated and released, according to police.

BTP Superintendent John Loveless said a total of 10 people were taken to hospitals by ambulance, and that an eleventh alleged victim went to a hospital on their own later Sunday night. Initially, Loveless said nine people appeared to have life-threatening injuries when they were taken from the scene.

The BTP said in a statement that it began receiving reports at 7:42 p.m. on Sunday about the stabbings aboard the LNER train that was headed from the city of Doncaster to London's King's Cross station.

"Our investigation is moving at pace and we are confident we are not looking for anyone else in connection to the incident," Deputy Chief Constable Stuart Cundy of the BTP said on Sunday afternoon.

Armed officers boarded the train when it made an unscheduled stop at Huntingdon, roughly 70 miles north of London, and arrested the suspect, whose name was not immediately released, according to Cundy.

"A knife was recovered by officers at the scene," the BTP statement said Sunday afternoon.

The suspect is from Peterborough in the county of Cambridgeshire, about 74 miles from London, according to Cundy, who also said investigators believe the suspect boarded the train at the Peterborough station.

"As would be expected, specialist detectives are looking into the background of the suspect we have in custody and the events that led up to the attack," Cundy said.

"This was a horrific attack that has had a wide impact," Cundy added. "My thoughts and those of everyone in the British Transport Police are with those injured and their families -- especially the brave member of the rail staff whose family are being supported by specialist officers."

The UK's Counter Terrorism Policing is supporting the investigation to establish "the full circumstances and motivation for this incident," the BTP said in a statement.

"At this stage, there is nothing to suggest this is a terrorist incident," Loveless said. "At this early stage, it would not be appropriate to speculate on the causes of the incident."

Speaking at the scene of the attack on Sunday morning, Loveless said the suspect was arrested within eight minutes of the first emergency call being received.

"The appalling incident on a train near Huntingdon is deeply concerning," British Prime Minister Keir Starmer said in a statement on social media. "My thoughts are with all those affected, and my thanks go to the emergency services for their response."

Home Secretary Shabana Mahmood said in a post on X that she was receiving "regular updates" on the investigation.

"Two suspects have been immediately arrested and taken into custody," she wrote, adding, "I urge people to avoid comment and speculation at this early stage."

King Charles III, meanwhile, said in a statement posted to the Royal Family's official X account, "My wife and I were truly appalled and shocked to hear of the dreadful knife attack that took place on board a train in Cambridgeshire last night."

"Our deepest sympathy and thoughts are with all those affected, and their loved ones," the king said. "We are particularly grateful to the emergency services for their response to this awful incident."

ABC News' Rashid Haddou and Somayeh Malekian contributed to this report.