11.20am UPDATE: The crash involved a Land Rover transporting a trailer of livestock, Gwent Police have confirmed.

The road was closed while several cows were rounded up on the carriageway.

Two injured cows had to be put down by their owner, the police added.

No people were injured in the crash.

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10.29am UPDATE: The road has now been reopened.

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A CRASH involving a Land Rover and trailer has closed part of the A449 dual carriageway in Monmouthshire, causing what are expected to be lengthy delays for traffic in the area.

Gwent Police are at the scene of the incident, on the northbound carriageway of the A449 near the Raglan junction.

Traffic Wales is reporting an overturned trailer in the centre of the carriageway.

The road "will remain closed for a significant amount of time", Traffic Wales added.

South Wales Argus:

Traffic cameras show a large build-up of traffic behind the scene of the crash, but vehicles on the southbound carriageway appear to be moving normally.

The A449 is the main road connecting central and northern Monmouthshire with Newport and the M4 corridor.

Twitter user Steve Jones sent us this photograph (below) showing the long tail backs on the northbound road.

Gwent Police have asked motorists in the area to find an alternative route.

The police have been contacted for more information.

More to follow.