The road between Letterston and Fishguard has been closed in both directions following a serious car accident on the A40.
One vehicle left the roadway between Letterston and Scleddau shortly before 12.17pm today (Thursday).
A 23-year-old man is being treated for serious injuries at the scene. The air ambulance is on standby and paramedics hope to get him to Withyybush Hospital shortly.
Two fire crews from Fishguard and Haverfordwest are in attendance. Police are directing traffic.
Major road diversions are being put in place and will be in effect for a number of hours.
Heavy goods vehicles will be diverted onto the St. David's coast road and all other traffic will be diverted at Letterston and at Manorowen road, Fishguard.