According to the city's emergency management headquarters, during a red alert, kindergartens, primary and high schools are advised to suspend classes, outdoor operations of construction sites are banned and some industrial plants are required to limit or stop production.

The notice, issued after days of heavy smog last week, also places traffic restrictions on certain types of vehicles in the city of 22.5 million people.

Car use will be limited as cars are allowed on the roads on alternating days depending on the odd or even numbers of their license plates. In addition, 30 percent of government cars will be banned from streets on an odd and even basis, the statement said.

According to the Beijing Municipal Environmental Monitoring Centre, heavy air pollution will linger until Thursday. It is expected to disperse Thursday afternoon as a cold front arrives.

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