Security forces in Beijing's co-host cities of Shanghai, Tianjin, Qingdao, Shenyang, Qinhuangdao and Hong Kong have been patrolling the ground and skies of all venues and the maritime safety of coastal venues.

Beijing metro passengers have been subjected to security checks since June 29. Locals have got used to the frequent presence of explosives sniffer dogs in metro stations and at the airport.

Paper metro tickets, which had been used for more than 30 years, disappeared from Beijingers' lives in early June, to be replaced by travel cards. And now commuters have bilingual direction boards with lively cartoon images showing the areas around the metro stations.

"Beijing's metro network is no different from that of Paris and is newer. It is convenient and safe, and the best part, no litter at metro entrances," said Hamath Sali, a Senegalese tourist.

Beijing and its citizens have taken the Games as a chance to upgrade the city's etiquette. To make sure that everyone knows how to behave, brochures were sent to 4.3 million families and training provided for 870,000 drivers, hotel service staff and booking clerks.

Authorities have been determined to change the city's bad hygiene image. More than 5,300 new public toilets have been newly built or refurbished, so that a visitor is never further than 10 minutes walk from a toilet in the downtown area.

In addressing the dog problem, Beijing introduced a "one family, one dog" policy in 2006, when it also joined a nationwide campaign against unregistered dogs. So far, the city's 700,000 dogs have been vaccinated.

Beijing authorities have also set up dog-raising discipline supervision committees in 95 percent of communities in urban areas and 85 percent of villages, where residents volunteer to check bad behavior by dogs and owners.

Beginning from June, the country's postal service has suspended mailing parcels containing liquids until October 31, following a previous liquid ban introduced in April on carry-on baggage in domestic flights. The ban was brought in for fear of terrorist attack following a failed attempt to blow up a Southern Airlines flight from Urumqi, Xinjiang to Beijing in March.

The city took 300,000 high-emission cars permanently off its roads last week, as part of measures to clean up the capital's air and ease traffic on the clogged highways.

The organizers announced its Olympic vehicle control plan earlier last month, which bans private cars on alternate days from July 20, depending on whether their number plates end in odd or even numbers. Half of local and central government vehicles will be off the roads during the event as well.

The measures could help reduce 63 percent of traffic pollution emissions in the city.