Beijing will replace or remove some 300,000 heavily polluting vehicles within one year in an attempt to further improve its air quality, authorities said on Wednesday.

All heavily polluting vehicles will be banned within the sixth ring road by Oct. 1 next year.

Currently, the number of heavily polluting vehicles accounts for about 10 percent of the total in the capital, but the pollutants they emit cover about half of the total from vehicles.

The air quality at night often showed a pollution peak, which was mainly due to the large number of such vehicles running into the downtown, according to Feng Yuqiao, a Beijing Environmental Protection Bureau official.

In the past decade, vehicle exhaust treatment has been an important part of the capital's efforts to improve air quality.

(Xinhua News Agency October 2, 2008)