(CNN) -- Seven people were killed and 15 others wounded Monday after a traffic collision in southwest China involving about 100 vehicles, state media said.
The pile up occurred in Guizhou province after a truck traveling in dense fog crashed into a gas station, the Xinhua news agency said. About 100 vehicles then crashed into the back of one another, local officials told Xinhua.
A Xinhua reporter at the scene reported that at 10 a.m. local, visibility on the highway was at less than 50 meters (160 feet).
Traffic was backed up roughly 20 kilometers (12 miles) following the collision, Xinhua said.