Several people have been rushed to hospital after hundreds of cars crashed into each other on a bridge in the shocking mass pile-up.

Rescue efforts continued throughout the morning in the fog on Zhengxin Huanghe Bridge in Henan, China, on Wednesday as vehicles were seen on other drivers' roofs following the mass collision, the Mirror reported.

More than 200 vehicles may have been involved in the crash, according to reports, including cars and larger lorries.

Foggy conditions on the bridge and icy road surfaces are thought to have contributed to the accident.

Dashcam footage posted online suggested incredibly poor road visibility at the location, with passengers from piled-up vehicles seen standing at the side of the road at intervals of several yards to try and flag down drivers approaching the scene.

Images showed a number of crumbled and smashed cars, while others were piled on top of each other. In one image, a 4x4 vehicle appeared to be almost entirely suspended on another car below it.

Smashed rear lights and other car exterior parts could be seen on the surface of the road.

Total numbers of injured and vehicles involved have not yet been confirmed, while a total of 11 people successfully rescued from trapped cars as of 9.30am local time.

State media reported that 13 fire engines and more than 70 firefighters had been deployed, with a large-scale operation underway to separate cars and rescue drivers.

Emergency services confirmed to Chinese media that no hazardous materials were involved in the crash.

The Zhengxin Huanghe Bridge crosses the Yellow River to connect the city of Zhengzhou with areas to the north, including the nearby industrial city of Xinxiang.

A similar pile-up in Henan back in 2018 due to thick fog left nine dead and eighteen more injured.

Authorities said the accident involved 28 trucks crashing into each other on the Daqing–Guangzhou Expressway in Pingyu County.