The red alert, the highest possible warning level, began on Tuesday morning and will last until midday on Thursday, BBC reported.

Limits have been placed on car use and some factories have been ordered to stop operations.

The alert comes as China, the world's largest polluter, takes part in talks on carbon emissions in Paris.

At 07:00 local time on Tuesday (23:00 GMT on Monday) , the air pollution monitor operated by the US Embassy in Beijing reported that the intensity of the poisonous, tiny particles of PM 2.5 was at 291.

The World Health Organization considers 25 micrograms per cubic metre to be a safe level.