Shijiazhuang, one of China's smoggiest cities, plans to cut coal consumption by 15 million tonnes in four years, including 4 million tonnes this year.

The capital of north China's Hebei Province, also plans to reduce iron and steel, coal carbonization, ceramics and chemical fertilizer production to cut emissions, said a city official on Friday.

Last year, the city poured 3 billion yuan (495 million U.S. dollars) of its own money, plus 8.5 billion yuan of social funds, into pollution control and ecological improvement, including relocating factories, emission reduction and tree planting, said the official.

The city wants a reduction of 6 percent in PM2.5 this year, and to get off the list of top five cities with poorest air quality.

Shijiazhuang is known for its dirty air and often ranks worst for air pollution in China. The air quality index in the city reached 500, "extremely hazardous", in late December and early January.

The average density of PM 2.5 -- airborne particles smaller than 2.5 micrometers -- was reduced by 8.7 percent in the second half of last year, local environmental protection bureau figures show.