A police helicopter was deployed to locate four people after a car overturned in Croxley Green on Friday night.
Hertfordshire Constabulary was called to Loudwater Lane at 11.13pm following reports that a blue Renault Clio had overturned.
Officers said a helicopter was called to trace two males and two females who are believed to have escaped uninjured from the car.
Police spokesman Sarah Spence said: "Officers attended the area along with the helicopter to try and trace the four people.
"It is not believed that anyone was injured and the vehicle, a blue Renault Clio, was recovered."
The police helicopter Twitter account posted at 11.50pm that the area had been cleared with a dog unit.
No further information about the incident has been released by police at this stage.
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