Two police officers were among five people taken to hospital after a police car and double-decker bus crashed on Saturday night.
It happened at around 9.15pm in Carshalton Road.
Additional police officers, ambulance and fire crews were called to the scene.
Firefighters released two people from the car.
Two fire engines from Wallington and Sutton fire stations and a fire rescue unit from Croydon Fire Station were at the scene.
London Ambulance service sent five ambulance crews, a clinical team manager, a medic in a response car, and an incident response officer to the scene.
Three people were taken to hospital and two to a major trauma centre.
A Metropolitan Police spokesperson said: "At about 21:15hrs on Saturday, 10 September a bus and police vehicle were in collision on Carshalton Road in Sutton.
"Additional officers, the London Ambulance Service and London Fire Brigade were in attendance.
"Two officers and several passengers, who were on board the bus, were treated at the scene.
"The officers and one passenger were subsequently taken to hospital. Their injuries were not thought to be serious.
"Enquiries into the circumstances are ongoing."
A London Fire Brigade spokesperson said: "Firefighters were called to a road traffic collision on Carshalton Road at the junction with Alma Road in Carshalton on Saturday evening.
"A car had collided with a double-decker bus.
"Firefighters released two people from the car who were taken to hospital by London Ambulance Service crews.
"Another three people were assessed on scene.
"The Brigade was called at 2119 and the incident was over for firefighters by 2214.
"Two fire engines from Wallington and Sutton fire stations and a fire rescue unit from Croydon Fire Station were at the scene."
A London Ambulance Spokesperson said: “We were called at 21:17 on Saturday 10 September to reports of a road traffic collision on Carshalton Road, Sutton.
“We sent a number of resources to the scene, including five ambulance crews, a clinical team manager, a medic in a response car, and an incident response officer.
“We took three people to hospital and two people to a major trauma centre.”
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