UPDATE 8.12am: All lanes have been reopened following the earlier accident, which involved a car hitting the central reservation.

But traffic remains slow between junctions 24 and 23a and congestion stretches back to junction 28 (Tredegar Park).

ONE lane of the M4 is closed, and there is queuing traffic eastbound - between junctions 24 (Coldra) and 23a (Magor services - following a crash.