China plans to invest 1.7 trillion yuan ($277 billion) to combat air pollution over the next five years, state media said on Thursday, underscoring the new government's concerns about addressing a key source of social discontent.

The money is to be spent primarily in regions that have heavy air pollution and high levels of PM 2.5, the state-run China Daily newspaper quoted Wang Jinnan, vice-president of the Chinese Academy for Environmental Planning as saying. Wang helped draft the plan.

Tiny floating particles, measuring 2.5 micrometres or less in diameter, are especially hazardous because they can settle in the lungs and cause respiratory problems and other illnesses.

The new plan specifically targets northern China, particularly Beijing, Tianjin and Hebei province, where air pollution is especially serious, the newspaper said.

The government plans to reduce air emissions by 25 percent by 2017 compared with 2012 levels in those areas, according to the report.

"The thick smog and haze that covered large areas of the country in January has focused public attention on this issue," Zhao Hualin, a senior official at the Ministry of Environmental Protection, told the newspaper.

China's State Council, its cabinet, approved the plan in June, Zhao said.

The newspaper said it was China's "most comprehensive and toughest plan to control and in some regions reduce air pollution by the year 2017".

The government plans to issue two more plans to address water pollution and improvements to the rural environment over the next five years, the report said.

In December 2012, China said it would spend 350 billion yuan ($56 billion) by 2015 to curb air pollution in major cities. The newspaper quoted Chai Fahe, vice-president of the Chinese Research Academy of Environmental Sciences, as saying that China's leaders realised, after releasing the plan in 2012, that a tougher approach against air pollution was needed.

Smog over northern cities in January generated widespread public anger as did the discovery of the rotting corpses of thousands of pigs in March in a river that supplies Shanghai's water.

Social unrest over environmental complaints is becoming common across China, to the government's alarm. Authorities have tried to assuage anger with measures that included empowering courts to mete out the death penalty in serious pollution cases.

But results have been mixed. Enforcement has been a problem at the local level, where governments often rely on tax receipts from polluting industries under their jurisdiction. – Reuters