Seven people were killed and four injured after a string of pileups on a section of expressway in east China's Anhui Province due to thick fog, Xinhua quoted traffic police as saying on Tuesday. Eighty-two vehicles, mostly trucks, were involved in 36 separate accidents early Tuesday morning on the Feidong county section of the expressway linking Xuzhou City to the provincial capital of Hefei. The collisions resulted in a 10-kilometer-long traffic jam. Dense fog that descended in the early hours of Tuesday reduced visibility to less than ten meters. Rescuers are clearing away the wreckage and the section of the road is expected to return to normal early on Wednesday.