BEIJING - An approaching cold front will help disperse smog in north China, said the country's environment watchdog on Sunday.

China National Environmental Monitoring Center said the smog in the Beijing-Tianjin-Hebei region will be gradually dispersed because of the cold air, but light to heavy air pollution is likely to continue in the region until Tuesday.

The National Meteorological Center renewed the yellow alert for air pollution in the afternoon.

The cold front is also forecast to bring gales and drag temperatures down in most parts of north China over the next three days, the center said.

China has a four-tier color-coded system for severe weather, with red being the most serious, followed by orange, yellow and blue.