Officers were dispatched to a Kitchener high school on Friday after threatening graffiti was found inside a washroom, according to Waterloo regional police.
They say members of the Eastwood Collegiate Institute community reported finding the graffiti at the school at around 11:25 a.m.
The graffiti included threats of violence toward the school, staff and students, and hate-motivated graffiti was located as well.
Police say they are continuing to investigate and are asking anyone with information to call 519-570-9777 or Crime Stoppers anonymously at 1-800-222-8477.