"Overall, China's water pollution is in a steady state, and there hasn't been a big improvement or a decline," SEPA vice minister Zhang Lijun told a news conference.

He said air in cities was getting better, but output of the major industrial pollutant sulphur dioxide reached 25.89 million tonnes in 2006, a rise of 1.5 percent on the previous year. COD, or chemical oxygen demand, a measure of water pollution, rose one percent.

Zhang said these rises were much less than years past -- up 5.6 percent for chemical oxygen demand and 13.1 percent for sulphur dioxide in 2005 -- and he expected more improvement this year, thanks to tougher inspections and greater deployment of water treatment and emissions technology.

"The year 2007 can reach a turning point, and total volumes of main pollutants will certainly fall," he said.

China is the world's largest emitter of sulphur dioxide from burning fossil fuels and smelting and causes acid rain.

Zhang's promise came as China's feverish growth drags officials, investors and citizens into increasingly tense conflict over the balance between growth and environmental health.

The country is also hastening to clean up for Beijing's Olympic Games in 2008.

China has promised to cut emissions of major pollutants by 10 percent between 2006 and 2010, but last year the country failed to meet the annual target.

Environment officials have said that attempts to punish companies that dump pollution have been stymied by local officials eager for investment, taxes and sometimes kickbacks.

An outpouring of outrage against a planned chemical complex in the eastern seaside city of Xiamen last week scared officials there into freezing construction and promising to reconsider the project.

Locals denounced the paraxylene plant as an "atomic bomb" menacing health, and they threatened to send nearly a million mobile phone text messages urging protests against its construction near the city centre.

In Wuxi in eastern China's Jiangsu province, locals have been complaining after tap water was unusable last week when a putrid canopy of algae blanketed Taihu Lake, China's third largest.

Algae can bloom in water rich in nutrients, often from farm run-off, industrial waste and untreated sewage.

Zhang acknowledged that nitrogen- and phosphorus-based pollutants, common in fertiliser, were rising in Taihu Lake and other water systems.