A stabbing has apparently taken place near Piccadilly Gardens, with two people reported to be injured.
Twitter user @BrokermanDaniel posted a video this afternoon which appears to show someone being treated by paramedics outside Morrisons.
Crowds have gathered and police have cordoned off the area.
A second video also shows more emergency services vehicles flooding to the scene to offer assistance.
Initial reports suggest two people have been injured.
Greater Manchester Police are apparently treating the incident as a "targeted attack".
Their statement reads:
"Police are currently responding to an incident near Piccadilly.
"At around 12.10pm today (Monday 10 February 2020), police were called to reports of an assault on Piccadilly, Manchester City Centre.
"Emergency services are currently in attendance.
"One man has been taken to hospital with injuries which aren’t believed to be life threatening. Another man is receiving treatment at the scene for minor injuries.
"An investigation is underway although officers are currently treating this as a targeted attack. There is no threat to the wider community.
"No arrests have been made.
"There are a number of road closures place and members of the public are being asked to avoid the area.
"Anyone with information should contact police on 101 quoting 1199 of 10/02/20.
"Alternatively, the independent charity – Crimestoppers, anonymously, on 0800 555 111."
More to follow.