Hundreds of protesters have taken to the streets of Montreal, many of them naked or barely clothed, to vent their feelings against the Canadian Grand Prix being held in the city at the weekend.
There have been reports of clashes between police and demonstrators, some of whom tried to enter a street party on Thursday night (local time) at the heart of celebrations around the race.
Organisers had earlier cancelled a free access day for spectators at the city's Formula One circuit due to fears that protesters might try to disrupt the event.
The protest is thought to be linked to a sometimes violent student strike that began in mid-February after the Quebec provincial government announced plans to raise tuition fees.