Hundreds of pro-Israel protesters gathered in Dorchester Square in downtown Montreal on Sunday afternoon.
Across the street, a dozen pro-Palestinian protesters encountered them, signs in hand.
Fighting erupted as Palestinians resorted to pro-Israel protests in support of Israel.
These meetings were declared illegal by the Service de Police de la Ville de Montreal.
Arriving by phone, spokeswoman Julian Lowesque confirmed the police presence to form a colorful crowd in the city center, without further ado, about the notice of the dispersal or arrests.
A report should be made one day later, as specified.
Pictures captured on the metropolitan streets in the afternoon showed clashes between protesters and strong police intervention.
A riot squad was on the scene to disperse the protesters.
Hostility at the summit
Meanwhile, in Gaza, Israeli airstrikes destroyed three buildings and killed at least 42 people, Palestinian aid workers said, adding that this was the deadliest attack in the military calm.
Despite efforts by the international community to mediate, the Israeli prime minister has said the dispute is over.
The fighting intensified last week, reaching its highest level since 2014.
In a televised speech, Benjamin Netanyahu said that Hamas wants to pay, which continues to fire rockets in civilian areas.
The Canadian Press and the Associated Press