A man has died and another male victim remains in hospital in critical condition following a double shooting at a school parking lot in Mississauga late Wednesday night.

Police were called to the scene on Montevideo Road, in the area of Glen Erin Drive and Battleford Road, at 11:10 p.m.

"There was some form of gathering here at the lot on the east side of the school," Const. Tyler Bell said. "The nature of that gathering is unknown at this time, but there was some sort of altercation that occurred between the two victims and either a suspect or suspects."

A young adult male and a middle-aged man were subsequently transported to a local hospital and one of them was then airlifted to a trauma centre via air ambulance, Peel Regional Paramedic Services said.

One of the victims – a man in his 40s – has since been pronounced dead, Peel Regional Police said Thursday morning. They said the other victim, a male under the age of 20, remains in hospital.

"The two victims are associated to one another. The nature of their relationship right now is unclear," Bell said.

The suspect or suspects fled the area, and there is no description of them so far, police said.

"At the time of the shooting, there are reports of vehicles leaving the area, but unfortunately it's too early to tell at the moment whether those are witnesses or suspects or just individuals fleeing the sound of gunfire," Bell said.

Numerous evidence markers were visible on the ground outside the school Thursday morning as officers continued to investigate.

Images from the scene show a number of emergency vehicles at the school and there is expected to be a heavy police presence at the school into the day. Officers are currently going door-to-door, canvassing neighbours in the area for footage.

However the school remains open today.

"So school is in session. We are working closely with the school obviously to maintain scene security and ensure the well-being of the students," Bell said.