An ambulance has been involved in a crash with a car at the Boundary junction between Cromer Road and Aylsham Road in Norwich.
No one is believed to have been injured in the crash, which happened at 11.45am, but there is debris in the road.
The crash, with a Fiat Idea car, has partially blocked the busy road but traffic is managing to move slowly in both directions.
A Norfolk Constabulary spokesman confirmed at 12.25pm that officers were awaiting recovery of the vehicles.
While a spokesman for the East of England Ambulance Service NHS Trust (EEAST) said there were no injuries suffered in the crash and confirmed that no patient was being transported in the ambulance at the time of the crash.
Ambulance service spokesman Gary Sanderson said: “An immediate investigation has been launched by our Trust to find out the cause of the collision this morning and we are working closely with Norfolk police.”