BEIJING, Feb. 22 (Xinhua) -- China's national observatory on Friday forecast that northern parts of the country would be shrouded in smog in the coming days while a rain belt will linger in southern regions for about a week.

Thick smog will envelop most northern areas including Henan, Hebei and Shandong provinces until next Thursday, according to the National Meteorological Center (NMC). The pollution in Beijing and surrounding areas will ease on Sunday and Monday thanks to cold air.

During the next week, many areas in south China will be swept with medium to heavy rain, with downpours expected in some places.

The NMC also renewed an alert for fog. Provinces including Hebei, Henan, Shandong, Jiangxi and Liaoning were covered with heavy fog Friday morning, with visibility reduced to less than 500 meters.