Beijing: World leaders and dignitaries are gathering in Beijing on Friday for the opening ceremony of the Olympic Games.

At least 10,000 people will perform during the opening, which is expected to be watched on TV by an estimated four billion people.

US President George W. Bush, who is expected to attend the opening ceremony, on Thursday expressed “deep concerns'' over human rights violations.

Bush voiced opposition to China's detention of dissidents. Protests against China's handling of Tibet have sparked arrests and marred the build-up to the Olympic games.

China spent $40 billion and seven years of planning for the Olympics, but has received criticism for putting curbs on journalists covering the Games and arresting protesters.

Jacques Rogge, the head of the International Olympic Committee, said he hoped the Games would help the world to understand China, and China to understand the world.