Smog began to cover parts of northern and central China from Sunday, and will cause medium-level or heavy air pollution in coming days, according to the National Meteorological Centre (NMC).

Medium to heavy smog will hit parts of Beijing-Tianjin-Hebei next Tuesday and Wednesday, though it would not be as severe as the air pollution earlier this week, Xinhua cited the NMC forecast.

All elementary and middle schools in Beijing will suspend outdoor activities as the city issued another orange alert for smog next week.

Elementary and middle schools, kindergartens and extra-curricular training schools should suspend their activities outdoors during the alert from Monday to Wednesday, said the city's education commission on Sunday.

The recent smog which dissipated on Tuesday prompted the Beijing government to issue its first orange alert, the second-highest level, which means construction sites must stop dust-raising activities while the elderly and the children were advised to stay indoors.