(Photo/Wang Guibin)

BEIJING, May 6 -- Beijing has banned restaurants from operating outdoor barbecues in selected suburban areas, extending a ban on the grills in the center of the city, municipal authorities announced on Wednesday.

Restaurant barbecues, which authorities say are a major contributor to smog, are no longer allowed in Tongzhou District and the Yizhuang Economic and Technology Development area, nor in parts of the Mentougou, Fangshan, Shunyi, Daxing, Pinggu and Miyun districts, according to the Beijing Municipal Bureau of City Administration and Law Enforcement.

And outdoor barbecues run by restaurants within Beijing's fourth ring road will continue to be strictly banned, the bureau said, reiterating a restriction first set last May.

Barbecuing is believed to emit a lot of PM2.5, harmful airborne particles measuring less than 2.5 microns in diameter.

Law enforcement officials with the bureau dealt with 2,214 outdoor barbecue cases from January to April, collecting fines amounting to 203,000 yuan (32,743 U.S. dollars).

To fight pollution, Beijing is aiming to keep coal consumption under 15 million tonnes, phase out 200,000 vehicles and close more than 300 polluting factories this year.

Officials have set the target of reducing PM2.5 in the capital city by 25 percent from 2012 levels by 2017.