A routine train ride turned into a scene of turmoil in eastern England when several passengers were stabbed aboard the speeding train.

Authorities have detained two men following the Saturday night incident, which resulted in injuries to nearly a dozen individuals.

Investigators are still piecing together the events leading to the attack, though preliminary findings suggest it wasn’t linked to terrorism.

Here’s what happened:

The train was heading for London

The train set off from Doncaster in northern England at 6:25 p.m., heading towards London’s King’s Cross station. At the midpoint of its two-hour trip, just after departing from Peterborough, police began receiving emergency calls about stabbings on the train.

Witnesses recounted scenes of chaos, with frightened passengers, some visibly injured, scrambling to escape the section where the assault was taking place.

Olly Foster said he heard someone yelling, “Run, run, there is a guy stabbing literally everyone,” and at first thought it was a Halloween prank — until he noticed blood on his hand from touching seats in the train carriage.

“Everyone was really pushing behind us, really panicking,” Foster told the BBC. He said he saw several people bleeding heavily from wounds.

Police responded within minutes

The British Transport Police, which handles security on the railways, said it received the first emergency calls at 7:42 p.m.

Within minutes, several dozen police officers, including specialist firearms officers, and paramedics were at the train station in Huntingdon, a town about 75 miles (120 kilometers) north of London.

Soon after, the train made an unscheduled stop at the station and passengers streamed onto the platform as armed police officers ran toward the train.

Two suspects were arrested

British Transport Police said that within eight minutes of the first emergency calls, officers from Cambridgeshire Constabulary, the local force, had boarded the train and detained two men.

Eyewitnesses said officers used a Taser to subdue one suspect who was holding a large knife.

Police said the suspects are both U.K.-born British citizens and described them as a 32-year-old Black man and a 35-year-old of Caribbean descent. They were being questioned at separate police stations Sunday on suspicion of attempted murder.

Two victims are in life-threatening condition

Police said 10 people were taken to nearby hospitals and an 11th went to a hospital on their own.

Initially, nine were classed as having life-threatening injuries. But on Sunday morning police said only two people remained in life-threatening condition. Four of the injured had been discharged.

Police seek a motive but say it’s not terror

Police Supt. John Loveless said counterterror police were initially called in to support the investigation, but that “at this stage, there is nothing to suggest that this is a terrorist incident.”

He said the investigation is being led by British Transport Police, and “it would not be appropriate to speculate on the cause of this incident.”

On Sunday the train remained at Huntingdon station and police wearing forensic suits, with a police dog, were working on the platform.

Leaders express sympathy

Senior politicians and royalty expressed concern and sympathy for the victims and their friends and families.

Home Secretary Shabana Mahmood paid tribute “to the exceptional bravery of staff and passengers on the train.”

King Charles III said he and Queen Camilla were “appalled and shocked.”

“Our deepest sympathy and thoughts are with all those affected, and their loved ones,” the royal couple said in a statement. “We are particularly grateful to the emergency services for their response to this awful incident.”