Montreal police will be on high alert Sunday for the Canadian Grand Prix, after a chaotic protest on Saturday night left several police vehicles damaged.

At least 28 people were arrested as protesters flooded the streets and attempted to crash a race party.

They were confronted and stopped by riot police armed with tear gas and pepper spray.

As some protesters battled with police, Canadian Press photographer Peter McCabe said some demonstrators took out their frustrations on police cruisers.

“Four police cars were trashed, vandalized with the red square (which) was painted on one, windows were broken on, I think three,” McCabe said.

The red square is a symbol of the student protest movement, with many students in Quebec fighting for lower tuition rates.

Meanwhile, Montreal’s subway system could be the scene of trouble on Sunday.

An anti-capitalist group is calling for disruptions on the subway line used to get people to the race track. They have called for supporters to pack the subway with as many people as possible.

The Grand Prix is one of Montreal’s biggest and most lucrative tourist attractions, but it has recently been denounced by activists as a symbol of capitalist excess.