Jim Carrey, Colin Firth and Bob Hoskins switched on London's Christmas lights on Tuesday and attended the world premiere of the 3-D film "A Christmas Carol."

The actors came to the British capital to promote Robert Zemeckis' animated movie, which features their voices.

The three stars turned on the lights at Oxford Circus and Regent Street _ London's main shopping areas _ and at St. Paul's Cathedral. After that, tenor Andrea Bocelli and the St. Paul's Cathedral Choir led more than 14,000 people in a Christmas carol event.

The new movie was later screened at a cinema on central London's Leicester Square.