A police officer was dragged along the ground by a car he had been trying to pull over.
The officer, who works as a dog handler, stopped the black BMW 5 Series in South Woodham Ferrers, Essex, at about 19:30 BST on Thursday.
When the officer tried to remove the keys from the ignition, the driver sped off and pulled the PC over, Essex Police said.
The police officer suffered grazes along his arm, legs and shoulders.
Essex Police said the vehicle was stopped as part of a routine inspection in Hamberts Road.
It was later found abandoned at the Whalebone Inn in the town but the driver has not been found, the force said.
The man has been described as tanned, aged in his 20s, with dark hair in a side parting and had scars over his face.
Police said the officer did not have a dog with him at the time.