A British police probe into a triple stabbing at a Manchester railway station on New Year's Eve which injured three people is now being treated as "a terrorist investigation", the city's top officer said on Tuesday.
Counter-terrorism police have arrested a 25-year-old man who remains in custody, and are searching an address where he recently lived in the northwestern English city, Chief Constable Ian Hopkins said.
The suspect reportedly shouted "Allah" during what Hopkins called a "horrific attack" on three people, including a police officer, at Manchester Victoria station on Monday evening.
A man and a woman, both in their 50s, are still being treated in hospital after sustaining "serious" injuries, while the officer was stabbed in the shoulder, Hopkins added.
"We are treating this as a terrorist investigation which is being led by counter-terrorism officers with support from Greater Manchester police," he told a briefing.
"They were working through the night to piece together the details of what happened and to identify the man who was arrested."
Hopkins said counter-terrorism officers were searching an address near the city centre "which is believed to be where the man had most recently been living".
Prime Minister Theresa May thanked emergency services for their "courageous response" in swiftly tackling the suspect.
She wrote on Twitter: "My thoughts are with those who were injured in the suspected terrorist attack in Manchester last night."
'Pure fear'
No group has claimed responsibility for the attack, which happened at around 8:50 pm (2050 GMT) when many revellers in the city would have been enjoying New Year's Eve celebrations.
Witness Sam Clack, 38, a BBC radio producer, said the suspect shouted "Allah" before and during the attack.
He also quoted the perpetrator as saying: "As long as you keep bombing other countries, this sort of shit is going to keep happening."
The witness added he heard the "most blood-curdling scream" and looked down the platform to see the attack unfolding.
"He came towards me," he added. "I looked down and saw he had a kitchen knife with a black handle with a good 12 inch (30-centimetre) blade.
"It was just fear, pure fear."
A general view of armed police officers at Manchester Victoria Metrolink station. Source: EPA
Clack said police used a stun gun and pepper spray before "six or seven" officers jumped on the man.
Video footage of the incident shows him being overpowered by the officers.
The police said he was arrested on suspicion of attempted murder and officers had recovered two knives from the scene.
The woman suffered injuries to her face and abdomen and the man was wounded in the abdomen, while a British Transport Police officer sustained a stab wound to the shoulder.
Their injuries were described as serious but not life-threatening.
'Dreadful'
The city's New Year celebrations went ahead in Albert Square despite the incident, with a firework display taking place as planned, though increased security was brought in.
British Transport Police said Tuesday its officers would be "highly visible through the national rail network".
Manchester Mayor Andy Burnham paid tribute to the emergency services' response.
He added the "vile attack" had "all the hallmarks... of an isolated incident".
Manchester police Assistant Chief Constable Russ Jackson said they were still trying to establish whether the suspect is a British national and how he came to be at the station.
"We are obviously considering his mental health given how frenzied the attack was, its random nature," he added.
"There is wide reporting... about what the attacker allegedly said during the incident.
"However it's really important to stress we are retaining an open mind in relation to the motivation for this attack."
A general view of police officers at Manchester Victoria Metrolink station Source: EPA
Police said investigators were considering its closeness to the Manchester Arena, where a suicide bomber struck in May 2017, as potentially significant.
The attack at a concert by the US singer Ariana Grande killed 22 people and wounded 139.
The perpetrator, Salman Abedi, 22, was born and raised in Manchester.
"That the incident happened so close to the scene of the terrorist attack on May 22, 2017 makes it even more dreadful," chief constable Hopkins said.
"Our work will continue to ensure we get to the full facts of what happened and why it took place."
