At least 10 people were rushed to the hospital after a stabbing spree on a train in the UK.

At around 7:42 p.m. local time on Saturday, Nov. 1, the British Transport Police (BTP) received reports that multiple people had been stabbed on a train service from Doncaster to London King’s Cross, according to a BTP news release. Armed police and paramedics arrived at the scene to find 10 people wounded.

Emergency services at Huntingdon Station, England.JUSTIN TALLIS/AFP via Getty

The victims were taken to a local hospital for treatment. Police confirmed in a press conference on Sunday that four people were later discharged, but two remain in a life-threatening condition. There have been no fatalities.

Two British nationals were arrested at the scene on suspicion of attempted murder, the BBC reported.

British Transport Police at Huntingdon Station.Chris Radburn/PA Images via Getty

Olly Foster, who was a passenger on the train, told the BBC that he initially thought the incident was a Halloween prank. He saw people running through the carriage and urging him to do the same as the stabbing attack unfolded.

“I put my hand on this chair just trying to push myself forward,” Foster recalled. “Then I look at my hand, it’s covered in blood. I look at the chair. There’s blood all over the chairs.”

Foster said passengers pulled the emergency alarm as an older man tried to prevent the attacker from stabbing a younger girl.

“We ran up the platform,” Foster recalled of the moment they escaped the blood-soaked carriage, per the BBC. “We ran out of the station, as we ran out of the station, we saw blue lights, so [police] were there very quick.”

Prime Minister Keir Starmer described the incident as “deeply concerning” in a post on X.

“My thoughts are with all those affected, and my thanks go to the emergency services for their response,” Starmer added. “Anyone in the area should follow the advice of the police.”

King Charles said in a statement on his Instagram Stories that he and Queen Camilla are “truly appalled and shocked” by the incident.

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

Prince William and Kate Middleton also spoke out about the tragedy.

A Kensington Palace spokesperson said in a statement: “I spoke to The Prince of Wales this morning, and he asked me to express his and the Princess of Wales’ thoughts for the families and friends of all those impacted by the horrific events last night near Huntingdon. He also wishes to express his thoughts are also with the first responders and train staff who acted so swiftly.”

Forensic investigators at Huntingdon train station.Joe Giddens/PA Images via Getty

The British Transport Police are being assisted by the Counter Terrorism Police amid their investigation, according to the BTP news release.

“This is a shocking incident and first and foremost, my thoughts are with those who have been injured this evening and their families,” said Chief Superintendent Chris Casey in the news release.

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

“Our response is ongoing at the station and will be for some time,” said Casey. “Cordons are in place and trains are not currently running through the area, and there are also some road closures.

“I thank the public for their patience and their cooperation this evening, which has already greatly assisted our policing response,” he added. “We will update you again as soon as we have more information.”

Huntingdon Station will remain closed, while there is an increase in police officers at other stations and on trains on Sunday, BTP said in an updated news release.

PEOPLE has reached out to the British Transport Police for further comment.