A teenage boy is in hospital after a stabbing at a west-end high school on Friday morning, Toronto police say.

According to police, there was a report of an altercation at Humberside Collegiate Institute, located near Quebec and Humberside avenues, at around 11:45 a.m.

Police said one teenage boy was stabbed at the school and he was transported to hospital with non-life-threatening injuries.

Investigators initially said that the suspect involved in the incident had fled the scene. In an update on Friday afternoon, police confirmed that a 16-year-old boy has now been arrested in connection with the stabbing. 

The school was placed under lockdown immediately following the incident but the order has now been lifted.

Insp Peter Wehby told reporters at the scene on Friday that the altercation began inside the school.

"I can't be specific as to where it started at this time," he said. 

He added that both the suspect and victim are students of the school. 

Wehby confirmed that there is a video circulating of the incident but said he had not yet had a chance to view it. 

"If anybody was videotaping, it is very important that they contact 11 Division and turn those videos over to the officers investigating this to assist us with this investigation," he added.