A woman has been airlifted to the Royal London Hospital with serious injuries after a car was in collision with a police Land Rover on the A12 in Essex.
The air ambulance was called to the scene at Mark's Tey near Colchester at 15:40 BST and the road was closed in both directions for the air ambulance.
The collision happened on the northbound carriageway which remained closed into the late evening.
Motorists are advised to avoid the area and diversions have been put in place.
A police constable driving the Land Rover was taken by ambulance to Colchester General Hospital with minor injuries.
