BEIJING - Major air pollutants, such as carbon monixude, carbon dioxide and particle matter emitted by vehicles have dropped by 20 percent in Beijing, thanks to the city's vehicle restrictions for the Olympics.

Twenty-two days out of the first 25 days in July reached the standard of "blue sky" days, or days with fairly good air quality, said Li Wei, deputy secretary general of the Beijing Municipal Government.

Beijing took 300,000 high-emission cars off its roads in early July.From July 20 private cars will be banned on alternate days according to their odd or even number license plates, in a bid to improve air quality and ease traffic congestion.

From June 23 to July 19, only half of the 22,800 vehicles used by all-level party organs, governments and public institutions under the Beijing administration were be allowed on the road.

Beijing had 145 "blue sky" days this year, 15 more than the same period last year, he said.

But residents and visitors still complain as the city is covered by mist and fog as usual.