People in Beijing have been told to fight smog by taking public transportation
Media playback is unsupported on your device

Air pollution levels in China's Beijing soar

21 February 2014 Last updated at 13:34 GMT

People in China's capital, Beijing, have been warned to stay indoors as much as possible to avoid outdoor air pollution that has reached hazardous levels.

Beijing's alert level is now set to "orange", the second-highest level possible.

The BBC's Celia Hatton in the capital has more.