A man has died after being struck by an ambulance transporting a patient near Sunderland, Northumbria Police said.
The force said it happened on the A19 shortly after 02:00 GMT.
The ambulance was travelling on the northbound carriageway and did not have its blue lights on when it hit the man, who was in his 30s and died at the scene.
No-one in the ambulance was injured and the driver, a man in his 40s, remained at the scene to assist police with their inquiries, the force said.
It happened on the A19 between the junctions for the A1018 and A690.
Officers from Northumbria Police's roads policing unit have launched an investigation and are appealing for anyone with CCTV or dashcam footage of the incident to come forward.
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