Forty-seven high-polluting factories will close in Urumqi, capital of Xinjiang Uygur Autonomous Region, as the municipal government plans to move the air polluters out of the city.

The listed 47 air polluters, mostly chemical plants and factories that process building materials, have agreed to leave the city before 2014, the Urumqi Environmental Protection Bureau said in a statement on Tuesday.

The removal will cost the government more than 3.5 billion yuan (533 million U.S. dollars), it said.

Urumqi has a severe air pollution problem, mainly caused by its industrial activities and heating supply. The city emitted 12.8 tons of sulfur dioxide and 6.1 tons of soot in 2009, which made it one of the worst polluted cities in China, said the statement.

"The air conditions are especially bad in winter -- if you view Urumqi from a distance, it looks as if the entire city is covered by a black pot," said a local resident surnamed Qi.

Many citizens said they welcomed the departure of the polluting factories, but much work remained to be done in reducing the city's pollution.

"Every winter, much coal is burned to provide heating, which causes a lot of pollution," said a local student surnamed Li. "The government also needs to improve the efficiency of the heating system."