A child has died and several others have suffered serious injuries after a truck and three cars crashed on the M5.

The incident happened near the Belmore Road overpass at Riverwood at about 8.20am and has shut all citybound lanes.

One child died at the scene while another, a 12-year-old girl, has been rushed to the Sydney Children’s Hospital in a serious condition.

A woman, who was trapped in the wreckage has since been freed, along with the three other drivers.

All have been taken to hospital with non-life threatening injuries.

#BREAKING: All eastbound lanes are closed on the M5 at Riverwood. #9Today pic.twitter.com/sk8Hs0d1kX

— The Today Show (@TheTodayShow) November 26, 2019

All citybound lanes of the M5 have now been reopened after the Crash Investigation Unit finished examining the scene.

Image: 9 News Sydney