With three days to go until the Olympic Games’ opening ceremony, China is taking no chances in fortress Beijing.
Organisers hope the focus will finally turn to sport after a build-up dominated by Beijing’s policies at home and abroad.
IOC President Jacques Rogge told President Hu Jintao and others the Games would be an historic milestone.
Security is particularly tight around the Olympic village.
Humidity has eased in Beijing today, improving conditions for athletes – and views of the new venues.
In the city of Kashgar, in the west, where 16 police officers were killed in what was being called a suspected terrorism attack on Monday, security was ultra tight.
All cars and buses coming in are being checked and riot police are stationed around the hospital where the injured are being treated.
A regional official says 18 so-called “foreign agitators” have been arrested in connection with the deaths. Two young men from the region’s Muslim Uighur community have also been detained.