Police were called at 8.25am to the A361, near Aller Cross at Barnstaple following a two vehicle collision between a car and a lorry.
Emergency services are currently on the scene assisting with three casualties, two of which are believed to have sustained serious injuries.
A road closure has been put on at the Landkey junction on the A361. The closure is likely to be on all day and motorists are being advised to avoid the area.
The carriageway is currently closed in both directions to allow the Air Ambulance to land.
If anyone witnessed this incident, please email firstname.lastname@example.org or call 101 quoting 0125 of the 31st July.