Police were attacked after being called to a Laval Moroccan festival Saturday night when a fight broke out between about 100 people.
Some of the attendees encircled police and started throwing rocks at them.
One officer and one person at the festival sustained minor injuries.
A 15-year-old was arrested.
Police said the people who were fighting were largely between the ages of 15 and 18.
It was the Moroccan festival's first edition and it took place near the Laurentian Autoroute and Du Souvenir Boulevard.
Police are discussing with organizers if the festival will continue Sunday.