Piccadilly Gardens has been cordoned off tonight after a serious 'police incident'.
There have been unconfirmed reports of a stabbing, with a victim said to be in a serious condition.
Trams have been stopped as a result.
The Manchester Evening News is attempting to contact Greater Manchester Police for comment.
Images and videos taken at the scene show a large police cordon in place.
It appears to start around the top end of Piccadilly Gardens, nearest to Portland Street, and stretch down to Market Street.
It's understood a rally had taken place at the gardens earlier on Thursday night.
Greater Manchester Police officers were at the scene.
Metrolink said that due to a 'police incident' no services were running through Market Street to Manchester Piccadilly railway station as a result.
Some lines were diverting via Exchange Square.
No services are running at Shudehill and Market Street either.
