A high school student is among two people shot dead in northwest Toronto on Monday afternoon.

Toronto police were called to the area of Dixon Road and Islington Avenue just after 12:30 p.m. ET.

Etobicoke.Double.Shooting.

Police tape surrounds the scene of a double shooting in the area of Islington and Dixon Road in Etobicoke. (Steven D'Souza/CBC)

The shooting happened behind an apartment building located at 2063 Islington Ave., near two schools.

"Once on scene, police found two people that had obviously been shot," Toronto police Supt. Ron Taverner told reporters on Monday afternoon.

"One of them was pronounced deceased at the scene, the second was transported to hospital by ambulance and has since been pronounced as deceased."

Police did not immediately identify the victims, both male.

Later Monday, Maria Rizzo, a trustee with the Toronto Catholic District School Board, confirmed to CBC News that one of the victims was a 15-year-old student from James Cardinal McGuigan Catholic High School.

Initial reports from paramedics had suggested that both victims were either in their teens or early 20s.

Taverner said police believe "at least two" suspects were involved. A weapon was not immediately recovered.

One person was taken into custody, but police did not describe the individual as a suspect.

A woman who saw the victims told CBC News that they were wearing Don Bosco Catholic Secondary School uniforms. Taverner later denied this.

'I heard 3 gunshots'

Michael Snary, who lives nearby on Islington Avenue, was walking his dog in the grassy area behind the building when he saw two groups of young people arguing. He said the group had come from the direction of the Don Bosco school parking lot.

"I thought there was going to be a fight, the way they were talking, yelling at each other," Snary told CBC News. "They moved behind this building and I heard three gunshots … and the kids took off. One kid ran down the hill and then collapsed at the side of the school.

"Here I am thinking the kids were just going to have a fistfight ... and then I heard the gunshots and that just brought it to another level."

'One kid ran down the hill and collapsed at the side of the school.'  — Resident Michael Snary

Police haven't released any information about possible suspects.

Snary said he's shocked the shooting happened so close to where he exercises his dog every day.

"It happens in a park where I walk my dog and a lot of other people do. Right now I don't know what to think. I mean, times have changed, these kids, it's obvious they solve things with guns."

Police have investigated more than 20 gun deaths in Toronto this year.

At a mayoral debate on Monday night, candidate Olivia Chow addressed the deaths of the two young males earlier in the day, along with the death of another man killed in a separate shooting on Sydenham Street.

"I can imagine the pain that the mothers and the families and their friends are experiencing right now," Chow said, renewing a call for a handgun ban in the City of Toronto. "It's really tragic that in this beautiful city of ours, we have gun violence."

Fellow mayoral candidate John Tory agreed the news of the three gun-related deaths was tragic.

"It's not the kind of thing that we expect to happen in our city," he said.

With files from the CBC's Mike Crawley and Steven D'Souza