A worker uses a welding torch to cut apart street barbecue ovens at an urban management bureau in Beijing, China, Nov 26, 2013. [Photo/icpress.cn]

BEIJING - More than 500 illegal outdoor barbecues, which media say cause "serious air pollution", have been destroyed in Beijing as part of an emergency programme to alleviate the city's often hazardous pollution.

The raids were part of a three-month operation to supervise the barbecues.

"Over 500 illegal barbecue grills in Beijing were destroyed on Tuesday amid the city's efforts to fight air pollution and lingering foggy weather," Xinhua reported on Tuesday.

Pollution often reaches hazardous levels and can cause long-term health issues. Chinese health officials say that lung cancer rates are rising among the city's more than 20 million residents.

China has adopted an emergency response programme to try to reduce the pollution, including alternating days for cars with odd and even licence plates to be on the road and closing schools when the smog is particularly heavy.

Smoke from factories and heating plants that encircle Beijing, winds blowing in from the Gobi Desert and fumes from millions of vehicles all contribute to the smog that often forms a thick blanket over the city.

Last winter the capital's smog was so bad it was dubbed the "airpocalypse", and there are concerns this winter will see a repeat after huge swathes of northeastern China ground to a halt in October when they were smothered by pollution.