Police say it appears someone may have used a pellet gun to put holes in several windows at École Musulmane secondaire de Montréal, located on Cavendish Boulevard in the city's NDG neighbourhood.
The building was closed over the weekend and no one was inside at the time. The school has about 100 students and was open for class on Tuesday.
Police say they will review the school's surveillance tape to see if they can find suspects and attempt to determine if the school was targeted because it's a Muslim school.
"We're looking at that possibility at this moment, if it is a hate crime, still to be determined but we're looking at that possibility," said Montreal police Const. Raphael Bergeron.
Bergeron is asking anyone with information to come forward.
The Quebec Collective Against Islamphobia condemned what it called an act of "hate," saying fear-mongering in the media was partly to blame for increased anti-Muslim sentiment.
"It’s a further sign of a deteriorating social climate for Quebec’s Muslims," Adil Charkaoui, the group's coordinator, said in a statement.
The group called on all levels of government to help in the fight against Islamophobia.