Toronto police are investigating a large brawl involving dozens of teenagers near a school in the city's Weston neighbourhood that resulted in the stabbing of a 15-year-old boy Tuesday afternoon.

Officers received a call shortly before 3:30 p.m. for a large group of people fighting on Ellis Avenue in the area of Jane Street and Lawrence Avenue West.

Acting Insp. Todd Jocko said up to 30 teenagers were involved in the altercation, which began near Weston Collegiate Institute.

Some of the teens subsequently made their way to Ellis Avenue, where officers located a 15-year-old boy stabbed in the torso.

Jocko said the victim was transported to the hospital with serious but non-life-threatening injuries. The boy is now in stable condition, he noted.

Officers later found two more teenagers, a 15-year-old and a 17-year-old, with minor injuries as a result of the fight. Jocko said the two boys were not stabbed.

It is unclear what led to the fight, and no suspect information has been released.

"It is unknown if the males were known to each other or if they were students at the school," Jocko said.

"Any violence that occurs in Toronto is upsetting, certainly if it involves youth or it's in the community. So we're certainly concerned about that. We are actively investigating it to determine exactly what happened and bring the involved parties to justice."

Ryan Bird, a spokesperson for the Toronto District School Board (TDSB) said the incident happened off school property and after school had ended.

"We will continue to work with students, staff, community members and Toronto Police to support in any way we can. We all play a role in helping make our communities safer,” Bird wrote in an email to CTV News Toronto.

A woman living in the area said she heard a noise, and when she went to check what was happening, she saw "a bunch of young boys" running.

One of the boys collapsed in front of her neighbour's door, she recounted. "So I just opened the door quickly. I said, 'This young boy needs help.' And that's when one of the friends yelled out, 'he's been stabbed.'"

The woman said she used a towel to stop the bleeding. "I was just talking to him, keeping him calm, saying 'you're going to be OK,'" she added.

Police are asking anyone with information, including those with dashcam or surveillance video, to contact them at 416-808-1200 or Crime Stoppers anonymously.