Cheering fans greeted the stars of the Harry Potter films in London Thursday, as they walked the red carpet ahead of the world premiere of Harry Potter and the Deathly Hallows: Part 2.

Armed with copies of the books and autograph diaries, fans screamed as Rupert Grint, Daniel Radcliffe, Emma Watson and other stars arrived.

Harry Potter and the Deathly Hallows: Part 2 is the eighth and final movie based on the series of books about the boy wizard written by J.K. Rowling. It premieres in North America next Tuesday.

Many fans had camped out for as long as four days to reserve their spot in Trafalgar Square, braving rain that made it almost impossible to sleep .

Radcliffe, taking a day off from his Broadway commitment in How to Succeed in Business Without Really Trying, and Rowling herself, wearing a long green gown decorated with flowers, drew rounds of applause.

'Bittersweet for Rowling'

Rowling said this premiere was "bittersweet" and that she approached it with a "mixed bag of emotions." She said she loves the young actors who have played her characters and has come to enjoy the filmmaking process.

 "I'm less nervous doing this. The first movie was absolutely terrifying, but now it's fun," she said.


From left, Daniel Radcliffe, Emma Watson and Rupert Grint in Harry Potter and the Deathly Hallows: Part 2. (Warner Bros. Pictures )

While Radcliffe has already gone on to new acting ventures, in productions of Equus in London's West End and New York as well as the musical How to Succeed in Business, some of the other Harry Potter actors are still feeling their way after the successful franchise.

Rupert Grint, 22, who plays Harry's friend Ron, says he's "looking for the next thing" after the Potter series ends.

"I've really enjoyed these last few films, because of looking back … knowing this is the end," he said on the red carpet. Grint recently wrapped filming of Comrade, a war movie by Norway's Peter Naess.

He said he will miss the Harry Potter series.

"It's been such a long time. It's been such a huge part of my life. It's hard to remember my life before this," he said.

Felton embraces villain roles

Tom Felton, who played Draco Malfoy, a wizard on the side of Voldemort, said he's hoping to "embrace the role of villain" as his career goes ahead.

"It's sad that it's coming to an end but it's great to end on such a high note," he said.

Matthew Lewis, who played Neville Longbottom, said it's been fun to see his own character develop.

"With this film, you really see the evolution of the character, you see him become a hero," he said.

The stars, who were cast in their roles as impressionable children have so far manoeuvred through 11 years of fame without any whispers of Lindsay Lohan-style meltdowns that can derail child actors.

Radcliffe, who was 11 when cast in the title role as the boy wizard for the first film, Harry Potter and the Philosopher's Stone, turns 22 this month. 

"In America, you're treated as an actor first and a kid second," he said in an interview last week. "Here, you're very much treated as a kid first and an actor second. In fact, you're not really treated as an actor. You're treated as a kid on a film set, which is how it should be, because that's all you are at that point. No one's an actor at 12."

With the performers so young, their parents were instrumental in steering the children through busy working lives and the madness of instant celebrity, producers said.

"We couldn't have done it without the family support that's kept all three of them and the supporting cast all lovely, lovely people," said David Barron, a producer on most of the Harry Potter films. "They've got very strong families who kept them really strongly grounded."

Most of the series was filmed at Leavesden Studios, northwest of London, giving the filmmakers a controlled environment where they could work and protecting them from unwanted publicity.

An 'incredible bond'

The group is very close, said Watson, who was 10 when cast as Hermione Granger and now is 21. She said she's finding it sad to know it's the last time they'll attend a Harry Potter premiere.

"We have this incredible bond. We've had such a singular experience that will tie us together for the rest of our lives," she said.

Watson, who had been studying at Brown University in Rhode Island, has voiced the animated film The Tale of Despereaux and starred  in a British TV series. But she says there won't be anything like Harry Potter.

"I'll miss being Hermione, living her life and ... [bringing to life] books that I've loved myself," she said Thursday.

With files from The Associated Press