Flights chaos as smog blankets Beijing

Beijing airport has cancelled hundreds of flights after dense smog reduced visibility in the Chinese capital.

Fog across parts of northern China meant motorways had to be closed.

Air quality in Beijing reached "hazardous" levels on Monday, according to the US embassy, which conducts its own measurements, while China's state Xinhua news agency said pollution was likely to reach "dangerous" levels.'¨'¨

Television footage of the airport concourse showed thousands of stranded passengers being turned away, or waiting around in hopes of booking later flights if the smog lifted. '¨'¨

Weather forecasts suggest the fog will continue until Wednesday.

The Chinese capital is considered to be one of the most polluted cities in the world.

Authorities in Beijing went to huge lengths to clean up the city's air ahead of the 2008 Olympics, shutting down coal-fired power stations and restricting the number of cars on the roads, but air quality in the city remains poor.