Heavy fog stranded more than 1,100 people at the airport after 13 flights were delayed in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region on Dec. 9, an airport official said.

Eleven other flights were forced to land in other cities such as Karamay in Xinjiang and Dunhuang in the neighboring Gansu Province.

The fog appeared around 9:00 a.m. and reduced visibility to less than 400 meters as of 2:40 p.m..