Several emergency response vehicles were filmed on social media outside the shopping centre.
The building was evacuated and armed police are at the scene this evening.
People who work in the shopping centre have reportedly been sent an alert to stay 600m away.
Initial reports of the incident came through at roughly 9pm.
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At 10pm Greater Manchester Police posted on Twitter : “Police remain in attendance at Manchester Arndale Centre following reports of a man with a knife.
“Officers attended and a man has been arrested and taken into custody for questioning.
“There are no reported injuries. There is not believed to be any wider threat to the community.”
North West Ambulance Service confirmed crews were called to the scene.
But a spokesman said there were no casualties or patients taken to hospital.
The front of the centre has been cordoned off.
A Twitter account which monitors traffic in Manchester said that several streets around the Arndale have been closed.
Last week three people were stabbed in Manchester Arndale and a man was arrested on suspicion of terrorism offences.