The terror suspect who was arrested after a “frenzied” New Year’s Eve stabbing which left three people hurt has been detained under the Mental Health Act.

Greater Manchester Police (GMP) said the 25 year-old, who is being held on suspicion of attempted murder, has been assessed by specialist medical staff. Police are searching his home.

A spokesman said: “The counter-terrorism investigation remains ongoing.

“There is nothing to suggest the involvement of other people in this attack, but confirming this remains a main priority for the investigation.

“The search of the address in Cheetham Hill continues.”

Prime Minister Theresa May joined British Transport Police in commending the emergency services for containing the threat during the incident, which occurred at around 9pm on Monday at Manchester Victoria Station.

Earlier, GMP Assistant Chief Constable Russ Jackson had said the suspect lived in the Cheetham Hill area of the city and counter-terrorism officers were at his address.

He said a couple aged in their 50s suffered multiple stab wounds in the “random” attack.

The suspect was heard to shout “Allah” and “Long live the Caliphate” during the incident at the station, which is next to Manchester Arena where suicide bomber Salman Abedi killed 22 people on May 22 2017.

Jackson said: “There is wide reporting in the press about what the attacker allegedly said during the incident and because of this we want to be clear, we are treating this as a terrorism investigation.

“However it’s really important to stress we are retaining an open mind in relation to the motivation for this attack.”

A man and a woman who were attacked suffered very serious injuries bu they are not life-threatening, he said.

A British Transport Police officer was also injured as officers on patrol bravely and immediately confronted the attacker with Tasers and pepper spray.

GMP Chief Constable Ian Hopkins said: “I know that the events of last night will have affected many people and caused concern.

“That the incident happened so close to the scene of the terrorist attack on May 22 2017 makes it even more dreadful.”

Jackson said police have recovered two knives, but do not yet know if both were used in the attack.

Sam Clack, a BBC producer, was on a platform at Manchester Victoria waiting for a tram home when he witnessed the attack.

The 38-year-old said: “I just heard this most blood-curdling scream and looked down the platform.

“What it looked like was a guy in his 60s with a woman of similar age and another guy all dressed in black.

“It looked like they were having a fight but she was screaming in this blood-curdling way.

“I saw police in high-vis come towards him.

“He came towards me. I looked down and saw he had a kitchen knife with a black handle with a good 12-inch blade.

“It was just fear, pure fear.”

Clack said police used a Taser and pepper spray before “six or seven” officers jumped on the man and held him down.

He said he heard the suspect saying: “As long as you keep bombing other countries this sort of shit is going to keep happening.”

Clack said it looked like both the man in his 60s and the woman with him had been stabbed, but both were conscious and were walked to a waiting ambulance.