A 17-year-old boy is in hospital with serious, but non-life-threatening injuries following a stabbing near a Toronto high school on Thursday afternoon.

Officers were called to Oakwood Collegiate Institute, in the area of St. Clair Avenue West and Oakwood Avenue, shortly before 1 p.m.

When officers arrived, they located a 17-year-old male victim with a stab wound to his midsection in a stairwell. He was transported to a trauma centre, where he remains in serious condition.

Toronto police initially indicated that the stabbing occurred inside the school, but in a subsequent update, they said it doesn’t appear that that was the case.

In a press scrum, Duty Inspector Peter Wehby said early police findings indicate the victim, a student at the school, had been stabbed off-site and then ran to the school to get help.

"We don't believe it happened on school property. We're fairly confident it did not. But I don't have the details as to what happened off property at this point," Wehby said.

No suspect information has been released. Wehby noted that police do not have motive for the stabbing, saying that it is still very early in the investigation to determine what exactly transpired.

He asked anyone with further information on this incident to contact Toronto police.

The school was placed under lockdown, but the order has since been lifted.

In a letter sent to parents, Principal Andrea Parise explained the details of the lockdown, and thanked school staff for their "calm and expertise" during the lockdown, a situation Parise called "very difficult."

"Our thoughts are with the victim and their family during this time, and we are hoping for a speedy recovery," she said.

Victoire Ndongle said he was coming back from lunch with his friends when the school went into lockdown.

"We were all pretty shook because you never know it could be your classmate, could be someone you sit right beside doing tests … and they could just be injured, and we never know what's going on," the 18-year-old student told reporters at the scene.

Ndongle said the school never provided an update on what was happening during the lockdown, leaving many students confused. He was locked inside a guidance classroom.

"We don't know what could go on. We don't know. We're not updated on anything. We don't know if it's someone in the school. We don't know what happened outside," he said. "It's pretty frightening."

Jermaine Harvey-Hyatt, who was with Ndongle in the guidance classroom, added that the ordeal was "pretty scary" but commended the staff for keeping students safe.

He said it was "terrible" that someone got stabbed.

"I hope he comes out safe. Any kid here, you know, it's a family here, so I hope he makes it out."