BEIJING, Feb. 26-- A strong cold front will sweep across northern China and help disperse the persistent smog that covers a vast part of the country, the national observatory forecast on Wednesday.

By early Wednesday, the cold air had arrived in Inner Mongolia Autonomous Region in north China and some northwestern regions, the National Meteorological Center said in a statement.

The cold front will move south to sweep across northern China, bringing temperature drops of up to 14 degrees Celsius.

Lingering smog in Beijing, Tianjin and Hebei Province will be dispersed after plaguing northern and central China for almost a week, the NMC said.

The center has issued 12 alerts for smoggy weather since Feb. 20, with 9 yellow alerts and 3 orange alerts. China's meteorological alerts are labeled blue, yellow, orange and red in order of ascending severity.