Cessnock District Rescue Squad and emergency services attended the scene around 5.40pm Monday and found the female driver trapped in the car, with three young children still inside.

Paramedics treated the injured woman and children, while rescue squad members assisted with the removal of the women and children from the vehicle.

One of the children was rushed by road ambulance to the John Hunter Hospital in a serious but stable condition with possible spinal, internal injuries and various lacerations.

The woman was transported by Westpac Rescue Helicopter to John Hunter Hospital in a serious but stable condition with possible fractures, internal injuries and leg lacerations, and the other two children were also taken by the Westpac Rescue Helicopter in a stable condition.

Cessnock Road was blocked in both directions with heavy afternoon traffic diverted around the scene via the back streets of Neath.

The NSW Police crash investigation unit is examining the circumstances surrounding the crash.