Even though Beijing has lifted the red alert for severe pollution, the capital city will remain in haze for a few more days.

The Beijing municipal heavy pollution emergency response headquarters issued a blue alert for heavy pollution in the city on Thursday afternoon, saying smog will hit central Beijing and southern suburbs on Thursday night. It called on residents in these areas to take protective measures.

A cold front will disperse the smog on Saturday, it added.

Roughly 50 cities in northern and eastern China have issued air pollution alerts in the most recent bout of smog.

China has a four-tier warning system, with red as the most severe, followed by orange, yellow and blue.