Five people were taken to hospital after four vehicles, including an unmarked police car, collided in Worcestershire.
The A4133 Ombersley to Droitwich road was closed for nine hours after the incident at about 1630 BST on Tuesday.
The vehicles involved were a Vauxhall Astra Envoy, which was the police car, a Mini Cooper, a Citroen Dispatch van and Mitsubishi, police said.
One person was airlifted to Worcestershire Royal Hospital.
No one was believed to have received life-threatening injuries, a spokesman added.
The road was blocked both ways until 0130 BST.