Days before the Olympic Games open in Beijing, the Chinese authorities have said they are confident that athletes and spectators will be safe.
This assurance comes after an attack which killed 16 policemen in the restive Muslim region of Xinjiang. Chinese media have blamed separatist Muslim militants for the attack.
A spokesman for the Beijing Games Organising Committee said preparations had been made to meet every conceivable threat at Games' venues.
The International Olympic Committee said it also believed the Chinese authorities had done everything possible "to ensure the security and safety of everyone at the Games".
In Monday's attack two men reportedly drove up to a border post in a rubbish truck and threw two grenades, before moving in to attack the policemen with knives. Both attackers were captured during the raid near the city of Kashgar, Xinhua state news agency reported.
Kashgar, known as Kashi in Chinese, is about 4,000 kilometres from Beijing, near the border with Tajikistan.
About 100,000 police and soldiers are on standby ahead of Friday's opening ceremony, and the already tight security has been stepped up in Tiananmen Square.
In Beijing, Chinese police and a small group of protesters clashed in Qianmen district, near Tiananmen Square.
The demonstrators complained that they had been evicted from their homes to make way for the reconstruction of the district, and had not received enough compensation.
The Olympic torch is due to be carried around a stadium in Mianyang, Sichuan province, which was used to house thousands of people forced from their homes by a devastating earthquake in May.
The torch will go on to the provincial capital in Chengdu on Tuesday before heading to Beijing for the opening ceremony on Friday.