A police officer has been airlifted to hospital with serious injuries after crashing into a brick wall and overturning.
The Hertfordshire Constabulary response officer was running to an emergency call at the time of the road traffic collision on A13 London Road in St Albans, Hertfordshire.
It happened at around 1.35pm, with collision investigation work now underway at the scene.
No one else is thought to have been injured in the crash.
One eyewitness told HertsLive that they saw eight police cars, five ambulances and four fire engines at the scene.
A police spokesperson said:
“Drivers carrying out essential journeys are asked to find alternative routes.
“Police, fire and ambulance and air ambulance are in London Road following the collision which happened near Cunningham Avenue by the railway bridge.
“A marked police car, which was responding to an incident, overturned after hitting a brick wall. The police officer has serious injuries and has been taken to hospital by air ambulance. No-one else was injured.”