Dusty dystopia: Biggest sandstorm in decade turns Chinese skies yellow

Beijing was cloaked in thick yellow smog on Monday with pollution levels surging off the charts as the worst sandstorm in a decade descended on China's capital from the Gobi desert.

City residents used goggles, masks and hairnets to protect themselves from the choking dust and sand, with landmarks including the Forbidden City partly obscured behind an apocalyptic-looking haze.

The city government ordered schools to cancel outside sport and events and advised the public to stay inside where possible, as hundreds of flights were cancelled.

Chinese weather agencies blamed the poor air quality on a sandstorm sweeping across northern China from northern Mongolia, where authorities there said it had left several dead, before being carried south by winds and reducing visibility in Beijing to less than 500 metres.

Under heavy skies, which draped buildings in an eerie glow, Beijing residents fretted over the health risks of a storm which compounded days of hazardous PM 2.5 pollution in the capital.

Beijing said last year it expected fewer and weaker sandstorms to hit northern China due to its reforestation efforts.

Discussion of the orange haze lit up online discussions -- with 230 million views on social media platform Weibo by Monday afternoon. Pollution in the city was at "hazardous" levels, according to air quality monitoring website Aqicn, as the reading soared off the scale for many apps.