LONDON (AP) — British police dismissed speculation on Sunday that a mass stabbing attack on a London-bound train the previous evening was terrorism-related and said two people who were wounded remain in life-threatening condition.

Police also said that two men, born in the United Kingdom, remain in custody at separate police stations. They were arrested eight minutes after the first emergency calls were made at 7:42 p.m. from aboard the train, where passengers had reported scenes of panic and chaos with many running through the carriages and some seeking safety in the toilets.

“This is a shocking incident and my thoughts are with those who have been injured and their families,” British Transport Police Superintendent John Loveless said outside the station in Huntingdon in eastern England where the train halted soon after the attack.

“There is nothing to suggest this is a terrorist incident,” he added.

The two arrested remain in custody, he said, adding that one is a 32-year-old Black British man, the other is a 35-year-old man of Caribbean descent.

Loveless also gave an update on the wounded, reducing the number in life-threatening condition from nine to two. He said four of them were discharged and that one other person arrived at the hospital, taking the overall number to 11.

After its emergency stop stop in Huntingdon, a market town around 120 kilometers (75 miles) north of London, bloodied and confused passengers spilled out of the train. Dozens of police waited, some of them armed, and the two suspects were arrested within eight minutes of the first calls to emergency services, Loveless said.

During the immediate response to the attack, police said that “Plato,” the national code word used by police and emergency services when responding to what could be a “marauding terror attack,” was initiated. That declaration was later rescinded but no motive for the attack has been disclosed.

“At this early stage it would not be appropriate to speculate on the causes of the incident,” Loveless said.

The attack took place as the 6:25 p.m. train from Doncaster in northern England to London’s King’s Cross station was about halfway through its 2-hour journey, having just departed from a stop at Peterborough.

Passenger Olly Foster told the BBC he heard people shouting “run, run, there’s a guy literally stabbing everyone,” and initially thought it might have been a Halloween prank — Saturday was a day after Halloween. But as passengers pushed past him to get away, he noticed his hand was covered in blood from a chair he had leaned on.

British Prime Minister Keir Starmer said his “thoughts are with all those affected” after the “appalling incident.”

King Charles III said he and his wife, Queen Camilla, sent their sympathies and thoughts to those affected and that they were “truly appalled and shocked to hear of the dreadful knife attack.”

London North Eastern Railway, or LNER, which operates the East Coast Mainline services in the U.K., confirmed the incident had happened on one of its trains and said there would be major disruption on the route until Monday.

British Transport Police’s Loveless said passengers will see a “high visibility presence of police officers at stations and on trains” on Sunday.