BEIJING -- The Beijing meteorological service has issued a yellow fog warning for several districts on Wednesday morning, with visibility in some areas falling below 500 meters, posing risks to transportation and public safety.

The warning covers districts including Daxing, Tongzhou, Chaoyang, Shunyi, Fangshan and Fengtai. According to the meteorological authorities, visibility and atmospheric diffusion conditions were significantly poor in the early morning, with reports of light to dense fog.

The National Meteorological Center also renewed a yellow fog warning at 6 am, indicating that foggy conditions would affect not only Beijing but also many other parts of the country from morning to noon. In some areas, including southern Beijing, visibility could be as low as 200 meters.

The public is advised to follow traffic updates, prioritize public transportation and remain vigilant on the roads. In addition, outdoor activities, such as high-altitude work, should be suspended for safety.

Meteorological departments forecast that visibility will improve from late night to Thursday morning due to northerly winds.

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