A terror suspect arrested after three people were stabbed at Manchester's Arndale shopping centre has been detained under the Mental Health Act.
A man armed with a large knife walked into the Exchange Court area of the building at 11.15am on Friday (2215 AEDT) and began lunging at shoppers.
A man in his 50s, a 19-year-old woman and another woman were rushed to hospital with stab wounds.
None of the injuries were thought to be life-threatening and both women were said to be stable, while two more women were also treated by medics.
Two unarmed police community support officers attempted to confront the assailant who chased them as they called for urgent assistance.
Witnesses described a scene of horror as shoppers sought refuge in stores.
Within five minutes, the knifeman was challenged and detained by armed officers in nearby Corporation Street at the side of Marks & Spencer.
A 40-year-old man from the Manchester area was arrested on suspicion of assault and then re-arrested on suspicion of commission, preparation and instigation of an act of terrorism.
Police later said he was detained under the Mental Health Act following an assessment by specialist doctors.
Assistant chief constable Russ Jackson, of Greater Manchester Police, said: "We do not know the motivation for this terrible attack. It appears random, is certainly brutal and of course extremely frightening for anyone who witnessed it.
"At this time we do not believe that there is anyone else involved in this attack but we will be constantly keeping this under review.
"We have specially trained officers supporting those injured from the attack.
"We'll have increased patrols, including armed patrols, in the city centre this weekend."
He appealed for anyone who was in the Arndale at the time to send any images or footage taken from the scene via the force's website.
One shop worker, who gave his name only as Jordan, 23, told the PA news agency: "A man was running around with a knife lunging at multiple people, one of which came into my store visibly shaken with a small graze.
"Soon after, security staff told all retail staff to close their doors and move the public to the back of the stores."
Freddie Houlder, 22, from Market Drayton, was in the centre when he heard "a load of screams just outside" the shop he was in.
He said a woman then came into the shop and told others "a guy just ran past the shop and tried to stab me".
Mr Houlder added: "Luckily she had quite a thick jacket - she thought originally it was a fake knife because of how easily it grazed off but police came in and said it was a real knife and she burst in to tears."
The shopping centre is just a few hundred yards from the Manchester Arena where 22 people were killed in May 2017 when Salman Abedi detonated a suicide bomb following an Ariana Grande concert.
Last New Year's Eve, three people including a police officer were seriously injured after a 25-year-old man launched a knife attack on passers-by.
He was arrested on suspicion of attempted murder and will face trial in November.
In 1996, the Arndale was damaged in a major bomb attack by the IRA in which a 1,500-kilograms device loaded on a lorry was detonated on Corporation Street.
More than 200 people were injured in the explosion, although there were no fatalities.