Beijing, Dec 6 (IANS): All elementary and middle schools here will suspend outdoor activities as the city issued another orange alert for smog next week, the state media reported on Sunday.

Elementary and middle schools, kindergartens and extracurricular training schools should suspend their activities outdoors during the alert from Monday to Wednesday, Xinhua quoted the city's education commission as saying on Sunday.

Classroom activities can be adjusted after being approved by the district-level education commission.

The recent smog that 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 are advised to stay indoors.

Some schools allowed students to choose whether to study at home or in school while Beijing Digital School is running classes online, according to the city Commission of Education.

The air pollution witnessed in Beijing and its surrounding areas is caused by vehicle exhaust emissions and coal burning in heavy industries and municipal heating in winter.