China hopes for 'greatest' Games

Seventeen of the 28 sports feature action on Saturday, with the Games running until 24 August. Seven golds are available on Saturday. American swimming star Michael Phelps begins his quest to win an unprecedented eight Olympic golds in a single Games as he competes in the heats of the 400m individual medley. In all, nearly 11,000 athletes from around the world will compete for around 1,000 medals in 302 events.

The Olympic football tournament began on Wednesday as China's women impressed. The host nation are fielding their biggest ever Olympic team with 639 athletes competing in all 28 sports at the Olympics for the first time, in a bid to top the medals table ahead of the United States. Other events taking place on Saturday's opening day include beach volleyball, men's gymnastics and rowing.

China has come under close scrutiny since Beijing was chosen in 2001 to host the Olympics. Demonstrations dogged the Olympic torch relay during its journey around the world. China's treatment of Tibet has been the subject of much of the controversy, and campaigners such as Amnesty International claim that journalists in China are still detained and websites blocked. Beijing has always promised to make improvements in human rights, media freedoms and the provision of health and education.

There has also been on-going concerns about the poor quality of Beijing's air, although Jacques Rogge, president of the International Olympic Committee, declared on Thursday that there would be no risk to the athletes.

The Games are expected to attract a record TV audience of four billion - over 100 million more than for the 2004 Athens Olympics. The action also takes place outside of Beijing, with Qingdao hosting the sailing competition and Hong Kong hosting the equestrian events. Tianjin, Shanghai, Shenyang and Qinhuangdao are the co-host cities for the football tournament.