A thick fog delayed about 100 flights and left more than 8,000 passengers stranded at an airport in southwest China's Sichuan Province Thursday.

"The heavy fog had blanketed the airport from about 5 a.m. to 9 p.m., which reduced the visibility to only 200 meters," said Lu Junming, of the Shuangliu International Airport in Chengdu, capital of Sichuan.

"We have to close the airport for more than four hours," he said.

All the flights scheduled at the airport for Thursday would be delayed for at least four hours, he said.

The airport authorities had distributed food and water to the stranded passengers, he added.

In addition, the dense fog led to a temporary shutdown of five expressways near Chengdu.