The file photo shows the smog in Shanghai. [Photo: people.com.cn]

　　Shanghai has halted work at some construction sites amid concerns over dust as the city suffers severe air pollution.

　　All local kindergartens, primary and secondary schools cancelled outdoor activities this morning.

　　Besides a smog alert, the authorities have adopted emergency measures for the first time this winter.

　　Drivers were warned of poor visibility and those prone to respiratory disease were advised to stay indoors and wear masks when venturing out.

　　The Air Quality Index suggested "heavy pollution" in the city Monday afternoon, and the figure continued growing with PM2.5 particles being the major pollutant.

　　The heavy air pollution has been blamed on pollutants from north China.

　　The situation is expected ease Tuesday afternoon thanks to stronger winds.