A pileup of more than 30 vehicles on a highway in eastern China has resulted in 18 deaths and at least 19 injuries, according to local police.

The accident happened around 7:40 a.m. on Wednesday on the expressway near Fuyang, a city in Anhui province. The cause of the mass collision is still under investigation, but police said they believe a sudden fog contributed to several accidents on the same stretch of road. Trucks, buses, and smaller cars collided, and four vehicles caught fire.

A video from Sixth Tone’s sister publication, The Paper, showed one car crushed between two trucks. Firemen and other rescue workers are on-site.

At least nine people are heavily injured and being treated at the hospital.

This article will be updated as more information becomes available.

Editor: Kevin Schoenmakers.

(Header image: A screenshot from a video shows the traffic accident on the expressway near Fuyang, Anhui province, Nov. 15, 2017)