A man is in critical condition after a shooting in downtown Toronto Friday evening.

Toronto police were called to a building on Sherbourne Street, north of Dundas Street East, around 6:30 p.m.

When officers arrived, they located a man believed to be in his 30s suffering from a gunshot wound.

The victim was taken to a trauma centre initially in serious but non-life-threatening condition—however, Insp. Andy Singh said the man's condition worsened and is now life-threatening.

Singh said the shooting occurred in a small parking lot behind the building.

The suspect was seen by witnesses and caught on surveillance video fleeing the area headed northbound on Sherbourne.

Singh said the Emergency Task Force also responded to the incident after receiving reports that the suspect was still in the building.

Police have not released a detailed description of the suspect.

"There is still a lot of activity in the area as we are pursuing leads," Singh said.

"There's a lot of people around here, and we're certainly hopeful that they'll come forward and provide us information as to not only what led up to the shooting, but if perhaps they can assist us in identifying the suspect."