Montreal: Protester threats have forced organizers of the Canadian Grand Prix to cancel the free opening day of the event.
Formula One fans were to have had access to Circuit Gilles-Villeneuve at the "Open House" event Thursday.
Instead the event was scrapped due to security concerns.
The student group CLASSE has suggested the race be used as a platform for the protesters` demonstrations over tuition fees.
Quebec Premier Jean Charest in turn has been critical of threats toward the race that generates an estimated USD 100 million in revenue for the city.
More than 300,000 spectators are expected to attend the June 8-10 event.