BEIJING - Local environmental authorities of Beijing said Sunday that a new bout of smog will hit the city from Sunday night to Tuesday.

According to the municipal environmental protection bureau, Beijing will see mild pollution, with the main pollutant being PM2.5, on Sunday. The Air Quality Index is expected to reach between 125 and 145.

Pollution will become severe on Monday and hit medium levels on Tuesday. Air quality will improve on Wednesday with the arrival of cold air.

The National Meteorological Center said smog will hit parts of north and central China starting Sunday.

The smog, which will hit Beijing, Tianjin, Hebei, Shanxi, Henan and Shaanxi, is expected to last until a cold front comes to the rescue around Thursday, the national observatory said.