The filthy air in the form of smog revisits China as a blanket of smog has covered north China as well as northwest China's Shaanxi Province since Wednesday, with air conditions in northern Chinese cities including Beijing and Tianjin severely downgraded.
Visibility in Beijing and Tianjin has reduced to less than 1 km due to heavy smog.
The situation is expected to worsen as some areas will experience torrential rains and thunderstorms.
Hazy skies leading to low visibility have forced people to stay indoors or use caution while venturing out. Sever pollution in Beijing also led to the enforcement of yellow alert in the city.
