BEIJING (REUTERS) - Authorities in Beijing plan to develop a network of ventilation "corridors" to help tackle the city's notorious air pollution, China's state news agency Xinhua reported on Sunday (Feb 21).

Construction in the zones, which will be created by connecting parks, rivers, lakes, highways and low building blocks, will be strictly controlled and obstacles to air flow will be removed over time, Xinhua cited Wang Fei, deputy head of Beijing's urban planning committee, as saying.

There will be five large corridors that will be more than 500m wide and several smaller ones, the report said, without giving a time frame for the project.

Pollution is a sensitive topic in China, spurring public protests every year about environmental degradation, particularly from factories.

For Beijing and its surroundings, the government has set a target for 2020 of reducing pollution by 40 per cent from 2013 levels. A senior environment official said on Friday (Feb 19) the city's air quality has improved over the last two years.

Beijing frequently features near the top of the list of China's most polluted cities as emissions from vehicles and heavy industry combine with weather conditions to raise smog levels. The worst bouts of air pollution tend to coincide with periods of low wind.

The authorities have increased efforts to reduce air pollution in the wake of the city's first "red alerts" in December last year, when hazardous smog engulfed the city.

Beijing will close 2,500 small polluting firms this year as part of efforts to combat pollution, Xinhua reported last month.