A 25-year-old man suspected of stabbing three people with a kitchen knife at Manchester Victoria train station on New Year's Eve was being held and assessed for mental health issues on Tuesday, police said, according to Reuters.
Greater Manchester Police were, however, continuing to investigate the attack because of suspected links to terrorism, they said in a statement.
A raid of the man's home in the city's Cheetham Hill area was still taking place, according to the report.
The man's name has not yet been released and police did not return requests for further information.
A witness, a BBC producer who was at the busy station during the attack, said a man stabbed several people at the station, shouting "Allah" and linking his actions to "bombings in other countries."
Two of the victims, a woman and a man in their 50s, were in a serious but not life-threatening condition, police said. The other, a male police officer in his 30s who sustained a stab wound to his shoulder, was released from hospital earlier.
"The Counter Terrorism investigation remains ongoing," police said. "There is nothing to suggest the involvement of other people in this attack, but confirming this remains a main priority for the investigation."
Prime Minister Theresa May said on Twitter on Tuesday, "My thoughts are with those who were injured in the suspected terrorist attack in Manchester last night. I thank the emergency services for their courageous response."
The station where the attack took place is very close to the site of the 2017 suicide bombing at the Manchester Arena, in which 22 people were killed and 59 wounded as they left a concert by pop star Ariana Grande.
Britain, which has been targeted by several terrorist attacks in recent years, remains on high alert.
In June of 2017, three terrorists drove into passengers with a van on the London Bridge, then proceeded to stab people at the nearby Borough Market, where they were eliminated by security forces.
In April of that year, a terrorist was arrested near Parliament before he was able to carry out an attack.
In August, a 29-year-old British citizen originally from Sudan rammed his car into several people before crashing outside Britain's Parliament, injuring three.