The latest instalment in the Chronicles of Narnia has shot straight to the top of the US box office.

Prince Caspian took close to £30 million last weekend to bump Iron Man off the top spot after two weeks.

Romantic comedy What Happens in Vegas, starring Cameron Diaz and Ashton Kutcher took third place.

Taken from the third book of the classic CS Lewis series, Prince Caspian stars British newcomer Ben Barnes who has a Hollywood lead role for the first time.

Barnes, 26, who played a small role in last year's fantasy adventure, Stardust, has never actually acted in a film with such a large budget, let alone one where an estimated £50 million has been splashed out.

He said he is a little shy of his new found fame. "A lot of people ask me about the attention and the responsibility of being in such a film and I'm getting used to it even though I wasn't ready for it."

At the moment the cast and crew are doing the promotional rounds and have been in Japan on a whirlwind tour to launch the film.

Director Andrew Adamson joined Barnes in Tokyo along with two of the four Pevensie children, the central characters in the book - Peter, played by William Moseley and Lucy, who is Georgie Henley.

New Zealander Adamson said he loves being involved in the magical franchise.

"It's always a pleasure to go back to Narnia. I visited Narnia the first time in my imagination when I was about eight-years-old and it's existed in my head ever since then.

"These films have given me the huge privilege of being able to take the Narnia from my mind and give it to the rest of the world to enjoy."

This time the film takes on a darker feel with the youngsters from the first film returning to Narnia to find the kingdom overthrown and under the control of an evil tyrant, King Miraz.

The follow up is already in the pipeline. The third instalment is the Voyage of the Dawn Treader.

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