An ambulance driver has been arrested on suspicion of drink-driving after being involved in a crash while answering an emergency call.
Four people suffered minor injuries in the seven-vehicle accident on the A52 near Bardills Island, Nottingham, on Saturday evening.
East Midlands Ambulance Service (EMAS) said the driver had been suspended and an inquiry launched.
A 39-year-old man was questioned and released on police bail until January.
One person suffered whiplash, one was treated for a suspected broken leg and another has a suspected fractured pelvis following the crash at about 1940 BST.
At the time, the ambulance was travelling to an emergency call and there was no patient on board, according to EMAS.
Diane Lee, director of operations, said: "We sincerely regret the injuries and inconvenience caused to members of the public involved in this incident.
"An internal investigation is being conducted into the circumstances of the incident.
"The driver of the vehicle was arrested at the scene and has been suspended pending the outcome of this investigation and the police enquiries."