Sir Frederick Banting Secondary School was put on lockdown after an incident between two people in the school’s yard.
Visual reports suggest one of the two people involved were in possession of a firearm.
London Police were called to the scene around 12:35 p.m.
Constable Jessica Mullen tells 980 CFPL an ongoing investigation is working to identify two possible suspects.
“These are all going to be youths so we would not be able to name them under the Youth Criminal Justice Act,” she said.
Mullen adds it was an isolated incident and that those involved were known to each other.
The lockdown was lifted at 1:55 p.m.