"The regional acid rain pollution is still out of control and even worse in some southern cities," Wang Jian, an official with the State Environmental Protection Administration, was quoted as saying.

Two major causes were the rapidly growing number of cars and increasing consumption of cheap, abundant coal as the country struggles to cope with energy shortages and meet power demand.

China is the world's largest source of soot and sulphur dioxide (SO2) emissions from coal, which fires three-quarters of the country's power plants.

More than 21 tonnes of SO2 were discharged in China in 2003, up 12 percent from the year earlier, the paper said.

"It is estimated that the country will consume more than 1.8 billion tonnes of coal in 2005, emitting an additional six million tonnes of SO2," Wang said.

The paper said the government was planning steps to rein in the problem, including setting quotas for SO2 emissions from thermal power plants and urging them to install desulphurisation facilities, through Wang admitted earlier efforts had led to no obvious improvements.

China has already banned the use of coal in some areas most severely affected by SO2 emissions, but sulphur is not the only enemy in the fight against acid rain.

"The amazing growth of nitrates, thanks to a swift rise of automobile and coal consumption plus overuse of fertilisers, is playing an increasing role in the country's acid rain pollution," Tang Dagang, director of the Chinese Research Academy of Environmental Sciences, was quoted as saying.