The Toronto film festival opened on Thursday with action movie "Looper" starring Joseph Gordon-Levitt, but it was "Twilight" star Kristen Stewart who attracted the biggest buzz on the red carpet at the star-studded festival scattered with Oscar hopefuls.

Anticipation was high for one of the world's premier film festivals that coming off Venice helps mark the beginning of Hollywood's awards season. Filmmakers see it as crucial launching pad and Toronto has previously propelled such films as "The King's Speech" to go on to success at the Academy Awards.

Ben Affleck, Selena Gomez, Halle Berry, Tom Hanks and rapper-turned reggae wannabe Snoop Dogg, now known as Snoop Lion, are all among a line-up of top stars due to appear.

But it was Kristen Stewart who wowed the red carpet Thursday, signing autographs to streams of cheering fans in her first media appearance since issuing an unusual public apology for cheating on long-term boyfriend and "Twilight" co-star Robert Pattinson with British film director Rupert Sanders.

Without directly referring to the scandal, Stewart, 22, told Reuters she was thankful "to know that everyone is here" and the support she described as "amazing" before she walked into the premiere of On the Road (2012) based on Jack Kerouac's seminal book of the post-war Beat Generation.

At a nearby theatre, Looper (2012), a futuristic action blockbuster featuring Gordon Levitt and Bruce Willis about an assassin haunted by his time-travelling future self, officially kicked off the 11-day festival that will screen more than 280 films.

Source: Press Release