BEIJING, March 17 -- Beijing will introduce vehicle-exhaust monitoring devices in a bid to tackle the pollution that continues to plague the city.

The new move is designed to strengthen controls on harmful emissions from the capital's 2.6 million vehicles, which are believed to contribute to around half of the city's ozone pollution, according to the Beijing Municipal Bureau of Environmental Protection.

Bureau official Wang Dawei said that ozone pollution, which has plagued many cities in developed countries since the 1950s, has recently become an increasingly grave problem in the Chinese capital due to the explosion in the number of cars.

"The exhaust-gas monitoring devices will be placed at several key sections in urban areas, mainly along the second and third ring roads," Wang told a news briefing yesterday, adding that motors exceeding emission standards will be fined.

Wang added that the devices would also provide valuable information on the overall situation of exhaust-gas pollution in Beijing, which he said was "fundamental" to the study of the city's ozone pollution.

He warned that this pollution could pose a major problem during the 2008 Beijing Olympics, as the strong summer sunshine would accelerate the formation of photochemical smog, which may damage health.

Besides placing monitoring devices on roads, the city is considering offering financial assistance to private owners of cars which produce heavy fume to purchase new cars whose exhaust-gas emissions meet the upgraded standards introduced in late 2005, said Pei Chenghu, the bureau's deputy director.

Meanwhile, around 8,000 of the city's old taxis and 2,000 buses will be required to have new technology installed that helps cut their emissions.

It is estimated that emissions from one old car are the same as from 14 new cars that meet the new standard.

Apart from vehicles, the city will also take steps this year to curb heavy pollution from around 200 plants in the power, petrochemical, steel and sewage treatment sectors.

All of these plants, which account for 80 per cent of the city's total industrial pollution, will be equipped by the end of this year with real-time monitors on their gas and water discharges.

Pei warned that the operation of those plants that exceed the discharge standards will be suspended or they may even be closed.

These moves are part of a raft of measures that the city's authorities have taken this year to tackle pollution.

Other steps include stricter supervision of construction sites and the expanded use of low-sulphur coal.

This year, the city has pledged that at least 238 days should meet good or excellent air quality standards.