Kristen Stewart hides when she sees teenage girls.

The 20-year-old actress - who plays Bella Swan in the 'Twilight Saga' movie series opposite boyfriend Robert Pattinson as vampire Edward Cullen - finds hysterical fans of the franchise so overwhelming that she thinks it is easier just to avoid them.

She said: "There's no way to eloquently put this. I just can't go to the mall. It bothers me that I can't be outside very often. And also to not ever be 'some girl' again. Just being some chick at some place, that's gone.

"Masses of girls identified with Bella in a really profound way, for want of a better world. The connection that I've seen people have. I've seen it physically. It's the characters they're flipping for."

Although she finds them terrifying, Kristen revealed she is conscious of how much the books and movies mean to the fans and hopes she is doing the character of Bella justice for them.

She said Bella is "a character who is embedded in so many people's psyches at this point."

She added: "It's starting to enter my head a lot more than it used to because it's at the end and it's come such a long way. I just want the fans of the book to be happy."

"I don't necessarily care about anyone else."

Although Kristen is enjoying a successful career - making a reported $25 million for the fourth and fifth instalments in the vampire franchise and recently filming 'On the Road' with Amy Adams - she admitted she would not have become an actress if she hadn't started so young.

Of her first role at nine years old, she told America's Vogue magazine: "At that time I just thought it was fun. I don't think I would ever have been able to be an actress had I not started at nine years old. I would have been the last person to stand up and say, 'I'd like to star in the play.'"