At least 18 people were killed and 21 others got injured in a more than 30-vehicle pile-up on an expressway in east China's Anhui Province on Wednesday.

A helicopter rushed to the scene as a flying ambulance for the first time in the province after firefighters pulled out 17 people from wreckages.

Four of the motor vehicles burst into flames as the pile-up snarled up 2.5 kilometers of expressway.

Unexpected occurrence of fogs had reduced visibility to within 100 meters on that section of the expressway.

Road management and traffic police are busily working to re-open that expressway.