China has speeded up its clean fuel programme and has started limiting poisonous substances in fuel in a bid to reduce automobile exhaust emissions, a state official has announced.

A spokesman for the State Environmental Protection Administration (SEPA) said that the standards have helped curb not only exhaust emissions but also noise and other pollution caused by growing number of vehicles, state news agency Xinhua reports.

A total of 34 items of exhaust emission standards for motor vehicles have been enacted and SEPA's monitoring centre for automobile emission has been co-operating with labs in the European Union, the United States and Japan in order to study the future of automobile pollution.

Beijing announced that SEPA and several other government departments are working together to regulate the maximum emission allowed for different types of motor vehicles throughout their life, including motorbikes and motor-driven tricycles.

China produced more than 4 million automobiles in 2003, half of which were sedans.

The country has become the fourth largest in the world for automobile production and the third largest country for automobile consumption, according to government figures.

The total amount of hydrocarbon and carbon monoxide emitted from motor vehicles in China reached 8.4 million tons and 36.4 million tons respectively in 2003.