A 23-year-old man has been arrested after a police officer was slashed with a sword, Greater Manchester Police (GMP) said.
The force said the officer is currently in hospital with “serious injuries” following the incident in Whalley Range at around 1.50pm on Sunday.
A number of roads remain closed around the scene in Demesne Road, GMP said.
One witness, who gave his name as Haroon, said he saw a man being arrested by officers on Upper Chorlton Road at around 2.50pm, who had been “attacking the police”.
Describing how the man was carrying a “3ft tool or sword”, he said he ran across the road into the front garden of a property on the street.
“From there the police tried to stun him because he wasn’t dropping the weapon ... I don’t know if the officer made a successful tase,” he added.
“He became even more aggressive and ran towards them with the weapon up in the air ... from there the officers tackled him, pushed him over and then I think he ran backwards and fell over.
“That is when the officer tried to disarm him, and you could see them using their weapons (batons) and they were hitting him on the legs - and he was not letting go.
“You could see him still hitting back while he was on the floor.”
He said the man “had hit a couple of the officers”, and added that he saw them bleeding - one from the lip or nose, and another at the top of their head.
He said the man appeared to be “out looking for trouble”, and was shouting during the incident. Greater Manchester Police said they were called at 1.50pm to reports of a man with a knife, and confirmed an individual was arrested at around 2.10pm.
The force said the injuries the officer suffered during the incident are to the face and back, and although serious, are not life threatening.