Seven people were killed in a four-vehicle pileup on Friday morning in southwest China's Guizhou Province.

It is not yet known if the accident caused more casualties as the rescue operation is continuing, said an official with the information office of the municipal government of Guiyang, the provincial capital.

The accident happened at around 8 a.m., when a truck carrying coal, two family sedans and a trailer collided on the highway in Guiyang.

Rescuers described a scene of destruction, as the truck was buried under coal, while the two sedans, sandwiched between the truck and the trailer, were deformed.

Police have cordoned off the site and traffic is limited to one-way.

Investigation into the cause of the accident is under way.