Scores of officers were dispatched to the shopping centre, which was evacuated shortly after 8:55pm on Friday.
Now Greater Manchester Police (GMP) has confirmed a 26-year-old man is being held in relation to the incident.
He was initially arrested on suspicion of affray, before being detained under the Mental Health Act.
The force added a woman had suffered a minor injury during the incident and was treated at the scene.
GMP said no other injuries were reported, and that officers were continuing to investigate the circumstances behind the incident.
It comes after four people were hurt at the Arndale centre after a man armed with a large knife lunged at shoppers a week beforehand.
Counter-terrorism police led the investigation on 11 October due to the location and nature of the attack, Greater Manchester Police said at the time.
Three people were taken to hospital with stab injuries, with a fourth person assessed and treated at the scene.
A 41-year-old man from the Manchester area was initially arrested on suspicion of serious assault but he was later rearrested on suspicion of the 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.