British police said on Sunday that a knife attack on a train was not being treated as a terrorist incident and two British men had been arrested on suspicion of attempted murder.
Officer John Loveless said of the nine people who were treated for life-threatening injuries on Saturday, four had been released from the hospital, and two remained with life-threatening injuries.
"Counter-terrorism policing was initially supporting our investigation. However, at this stage, there is nothing to suggest that this is a terrorist incident," Loveless told a news conference.
He said the men arrested were a 32-year-old Black British national and a 35-year-old British national of Caribbean descent.
Earlier in the day, counterterrorism police were helping to investigate the stabbing of 10 passengers on a train in eastern England on Saturday.
Ten people were taken to the hospital, of whom nine are described as having suffered what are believed to be life-threatening injuries, the police said.
Prime Minister Keir Starmer called it an "appalling incident" which was "deeply concerning," while Interior Minister Shabana Mahmood said she was "deeply saddened" and urged people to avoid comment and speculation.
The government is keen to stop rumors spreading on social media following an incident in Southport in northwest England in 2024, when internet claims over the murder of three young girls sparked days of rioting across the country.
Healey told the BBC that he was confident police would soon provide more information.
"They will let us know as much as they can, as soon as they can," he said.
Witness Olly Foster told the BBC that he was on the train when someone ran past him saying a man was stabbing "everyone, everything."
"I put my hand on this chair...and then I look at my hand, and it's covered in blood. And then I look at the chair, and there's blood all over the chair. And then I look ahead and there's blood on all the chairs," he said.
Another witness told Sky News that a suspect was seen waving a large knife before being tasered by police.
Britain's current threat level from terrorism is rated as "substantial" by security services, meaning an attack is "likely."
After a number of serious attacks in 2017, Britain has had some quieter years in the 2020s, although last month three people were killed when a synagogue was attacked in Manchester.