Footage has emerged from China of thousands of travellers stranded in an airport because of heavy smog.<br /><br />In the video, filmed in Chengdu, Sichuan Province on Sunday, planes can be seen grounded on the tarmac in the thick fog, while over 20,000 of travellers wait to board.<br /><br />The runaway was reportedly closed for ten hours, causing 49 flights to be cancelled and more than 20,000 travellers to be stranded in the airport.
