Keira Knightley and Carey Mulligan on the red carpet

British actresses Keira Knightley and Carey Mulligan have helped launch this year's London Film Festival with the European premiere of their latest film.

The pair joined co-star Andrew Garfield on the red carpet at a gala screening of dystopian drama Never Let Me Go.

Based on Kazuo Ishiguro's novel, Never Let Me Go tells of friends who grow up at boarding school, unaware of a dark secret that looms over their future.

Directed by US film-maker Mark Romanek, it will be released in the UK in January.

The 54th BFI London Film Festival runs until 28 October.