The A40 between Haverfordwest and Canaston Bridge has been closed following a serious collision earlier this afternoon.
Two vehicles are understood to have been involved.
Dyfed-Powys Police have said that the road - one of the main routes into Pembrokeshire - could be closed until midnight.
The travel situation is likely to be made worse by the fact that the Cleddau Bridge is currently closed to high sided vehicles due to the strong winds hitting the county.
The latest travel information can be seen here.