Torch bearers left the Forbidden City and will carry the flame to landmarks such as Tiananmen Square ahead of Friday's opening ceremony of the Games.

The torch has travelled 140,000km (87,000 miles) through six continents since it left Greece on 24 March.

On Tuesday, the flame passed through Sichuan province, which was devastated by an earthquake in May. A minute's silence was held in Guang'an city, honouring almost 70,000 people who were killed in the quake.

Cheering, flag-waving crowds acclaimed the Olympic torch as it began its last leg on Wednesday.

Chinese astronaut Yang Liwei and basketball star Yao Ming are scheduled to join more than 800 torch bearers taking part in the three-day relay across the city of 17 million people.

A spokesman for the organisers said preparations had been made to protect some 10,500 athletes from 205 countries during the Olympics.