Firework displays, parties and other celebrations have taken place around the world to usher in the new year.
US revellers cheered the traditional ball drop in New York's Times Square to mark the start of 2011.
Earlier festivities ranged from the release of thousands of silver balloons in Tokyo, to the first countdown of a western new year in Hanoi, Vietnam.
In Sydney, crowds watched what is hailed as the world's biggest New Year's Eve fireworks display.
Dubai saw a spectacular laser and fireworks show at the Burj Khalifa, the world's tallest building. BBC News
