The British actor says he worries about being infected with HIV when obsessed followers approach him with open wounds and ask him to suck their blood.

Pattinson, who plays vampire Edward Cullen in the series, has revealed he genuinely fears for his life when fans mob him in the street.

The 23-year-old actor laid out his concerns to promote a new biography ahead of the next Twilight film, New Moon, which premieres this week.

Pattinson recalled one time where a group of girls approached him bleeding from scratches they had just opened up on their necks.

"People ask me to bite them and want to touch my hair. I just don't want someone to have a needle and give me HIV and I don't want to get shot or stabbed,” the News of the World quoted him as saying.

"There were girls who had scratched the side of their necks, so they were freshly bleeding when they came up to get a signature. They were like, ''We did this for you''. I didn't know what to say. ''Thank you, guys?''

"This is my life. People know my name and ambush me in public and try to figure out what hotel I'm staying at. I have accepted it as real now, but it still feels surreal," he added.

Pattinson was mobbed in London's Leicester Square last week at an event for ‘New Moon’, second movie in the blood-sucking film series.

But Pattinson says he feels vulnerable at big film events such as premieres, where he could be the target of an overly obsessive fan or even a terror attack.

He said: "Oh my God. Are they going to blow the place up?"