George Clooney and Sandra Bullock sail in for Venice Film Festival

Hollywood stars George Clooney and Sandra Bullock have arrived in Venice to open the city's film festival with their sci-fi thriller Gravity.

The pair sailed up one of the city's famous canals before posing for photographers and signing autographs for waiting fans.

Wednesday's world premiere of Alfonso Cuaron's film will kick off 11 days of screenings and parties as the Italian festival celebrates its 70th edition.