A boy is being treated for significant head injuries after being hit by an ambulance as it answered a 999 call.
The child, believed to be 10, was struck by the South Western Ambulance Service vehicle in Bath, Somerset, just after 4pm on Thursday, an ambulance spokeswoman said.
He was first taken to Royal United Hospital but later transferred to the specialist major trauma unit at Frenchay Hospital, Bristol, where he remains in a stable condition, a hospital spokeswoman said.
The accident happened at the junction of London Road and Snow Hill near the River Avon, as the ambulance responded to a 999 call.
The South Western Ambulance Service spokeswoman said: "Due to the serious condition of the patient, police gave permission for the ambulance to leave the scene to take him to hospital.
"Clearly our primary concern is for the patient and his family - senior executives from South Western Ambulance Service have travelled to Bath and will offer to meet with the family.
"We are also ensuring the crew involved are fully supported.
"We are also working closely with the police to ensure the circumstances surrounding this serious incident are fully investigated."
She later added: "He was transferred to Frenchay Hospital because he is suffering from head trauma and the hospital has a specialist major trauma unit."
London Road was closed in both directions following the accident, while police investigated the crash.