Beijing issued a blue alert for heavy air pollution Friday as a new round of smog hit the city, authorities said.
The alert, effective from 5 p.m., is forecast to last one day, according to a statement by the city's air pollution emergency response office.
Air quality will improve Saturday night when a cold front is expected, according to the statement.
Beijing has a four-tier color alert system for pollution, with red being the highest, followed by orange, yellow and blue. The blue alert means the air quality index is forecast to reach between 200 and 300 PM2.5 for one day.
