Two lanes are currently blocked on the M4 eastbound following reports of a collision between Junction 32 Coryton and Junction 30 Cardiff Gate.
Traffic Wales has issued a warning to motorists, confirming that congestion is now building in both directions as a result of the incident.
Traffic officers are on their way to the scene to assess the situation and assist with managing the disruption. Drivers are being urged to take extra care when travelling through the area and to allow additional time for their journeys.
Queues are already forming on the eastbound carriageway, with knock-on delays affecting vehicles heading westbound as well.
Motorists are advised to consider alternative routes where possible and to keep up to date with the latest travel information before setting out.
Further updates are expected once emergency services arrive and the full circumstances of the collision become clear.
