GWENT Police are appealing for witnesses to a crash on the A40 to Monmouth after a driver involved fails to stop after the accident.

Emergency services were called just after midday today to the scene of a road traffic collision involving two vehicles on the A40 near the Gibraltar Tunnels.

The collision involved a black Ford Fiesta or Focus, being driven by a white male, believed to be between 20 - 30- years-old, and a green Vauxhall Agila, being driven by a man in his fifties. The Vauxhall also contained a female passenger and two children, a seven and 14-year-old in the rear of the vehicle.

As a result of the collision, the Vauxhall Agila left the carriageway and went down an embankment into trees. The driver of the Ford did not stop and was last seen turning left at the traffic lights, into Monmouth.

The driver and children in the Vauxhall have been taken to Neville Hall Hospital with minor injuries. The woman was taken to the Heath Hospital in Cardiff by Air ambulance with what are described as serious leg injuries.

The Northbound A40 has been closed for vehicle recovery and diversions are in place.

Anyone who may witnessed the collision or has any information about the driver of the black Ford is asked to ring 101 quoting log 300 15/02/14.