Sandstorm hits northwest China leaving city smothered in yellow fog

A storm has blasted a city in China with a "sand wall" almost 100m high.

Zhangye City, in the country's Gansu Province, was battered by winds travelling at around 17 meters per second, which engulfed the city in sand and dust at around 4pm local time on Sunday.

Visibility was reduced to less than 10 metres.

The fire department activated an emergency response plan and police carried out two-way patrols on motorways.

Associated Press contributed to this report