Beijing has shunted 13,000 outdated, polluting taxis onto the scrapheap since the beginning of 2006 to try and reduce air pollution, said the local legislature.

They will be replaced by new taxis that meet the Euro-III emission norm, said Liu.

Some 2,000 outdated buses will also go to the wreckers this year and 2,760 clean gas-driven buses will go into service.

The city renovated 330 coal-fuelled boilers and replaced 28,000 old taxis and 3,900 diesel-engine buses in 2005.

Automobile emissions containing sulfur dioxide have become a major factor in urban pollution. Sulfur dioxide emissions increased by 4.2 percent in the first half of the year over the same period in 2005.

Statistics show that Beijing has 2.8 million registered motor vehicles, including 67,000 taxis.

China will introduce new motor vehicle emission standards in 2007 that will cut automobile pollutants by 30 percent, the State Environmental Protection Administration (SEPA) has said.

The new standards match the EU's Euro III standards. A more stringent standard, equivalent to Euro IV, will come into effect in 2010.

China began enforcing Euro II emission standards nationwide in September 2003.

Other measures -- including fume desulphurization at three power stations and increased supervision of flying dust on construction sites -- will also be implemented next year to combat pollution.