Beijing is waging a war against air pollution and it is doing so one barbecue at a time.

Authorities in the capital have destroyed more than 500 open-air barbecues "to cut PM2.5" _ the tiny particulate matter in the air that can enter deep into the lungs.

Photos carried by state media showed workers on Tuesday cutting pieces of metal with sparks flying as city wardens looked on.

Citizens online ridiculed the exercise, suggesting authorities should focus on bigger sources of pollution.

A media officer at Beijing's Xicheng district administration bureau said the hundreds of barbecue grills were confiscated over a three-month campaign and cut up so they couldn't be used again. She refused to give her name, as is common with Chinese officials.

Beijing's pollution regularly reaches hazardous levels. The city government announced last month that emergency measures such as factory shutdowns and traffic limits would kick in when air pollution levels are particularly heavy.