The Guardians Of The Galaxy took a break from their defending duties as they touched down in London for the film's European premiere.

Thousands of fans waited for hours to catch a glimpse of the stars of Marvel's latest blockbuster including Zoe Saldana, Chris Pratt, Vin Diesel and Dave Bautista as they stepped out on the red carpet at the Empire Cinema in London's Leicester Square.

Former Doctor Who actress Karen Gillan, dressed in a jumper, A-line quilted skirt and boots all by Louis Vuitton, also attended alongside the film's director, James Gunn.

"To be part of the Marvel universe is a dream come true," Karen said. "I have a letter saying, 'Welcome to the Marvel universe', which is framed in my house. It's in the living room for everyone to see."

Zoe, rumoured to be pregnant, looked stunning in a floaty Valentino gown, which disguised any sign of a baby bump. The 36-year-old said she threw herself into the fight scenes as her character, lean, green fighting machine Gamora.

"It was great because I love to be able to express my physical ability in the characters I play and I demand that," she said. "I also think it's a very strong message for young women to be more physically active. Don't let the boys have all the fun all the time."

She continued: "If I was going to join the Marvel universe, it was going to be with an antihero character. I am a number one fan of Marvel movies but the one thing that was always missing for me was that they are so perfect. These Guardians are underdogs so I knew the audience would identify with at least one of them."

The film follows a group of misfits - alien Gamora, human Peter Quill/Star-Lord (Pratt), tree-like humanoid Groot (Diesel), Rocket Raccoon (voiced by Bradley Cooper) and vengeful warrior Drax the Destroyer (Bautista) - who team up to save the galaxy.

Chris Pratt, who is married to actress Anna Faris, joked: "Everyone in the household has to call me Star-Lord. It's going to be like that for the next 10 or 20 years. No, everyone calls me Chris."

Vin Diesel, who utters the line "I am Groot" throughout the film, arrived last, wearing the stilts he wears as his character.

"He is the most innocent character I've ever played. He is also the strangest character I've ever played. Thanks Marvel for opening up the universe," the actor admitted.

Karen, best recognised as the Time Lord's companion Amy Pond in the BBC sci-fi series, admitted she was overwhelmed by the huge crowds.

"This is crazy. The energy here is insane. I've never been to a premiere of this size before so this is really exciting to be involved in it," she said.

Professional fighter Bautista added: "This is very overwhelming. I'm introverted by nature so all this will always be strange to me. I just want to curl up in a ball and hide."

Chris Hemsworth, who plays Thor in the Marvel films, Avengers director Joss Whedon and Mark Hamill, who reprises his role as Luke Skywalker in Star Wars: Episode VII, also attended the premiere.

Guardians Of The Galaxy opens in UK cinemas on July 31.