Beaconsfield High School was on lockdown for a brief time this afternoon because of a brawl which left one girl injured.
Police say the incident happened just after noon, and didn't actually happen at the school, but at a nearby strip mall.
Witnesses say two girls got into a fight, one of the teens pulled a knife and slashed the other girl in the forehead and arm.
A 15 year old girl is in custody.
The teen that was cut was brought to hospital and will recover.
Witnesses tell CTV the conflict began in class but quickly degenerated into an armed attack.
“She ends up pulling out a knife on the girl and then tries to stab her in her gut,” said one teenaged witness who asked not to be identified.
Beaconsfield High is south of Highway 20 and has about 900 students.
With files from CTV Montreal