A car has been badly damaged in a collision involving a police car in Northampton.
Luke Cook saw the aftermath of the crash by the Shell Garage on London Road, East Hunsbury, which eyewitnesses told him had occurred while the police car had its blue lights on.
Mr Cook said that three police cars arrived at the scene within minutes, though the ambulance service had not arrived by the time he left.
A police spokeswoman said the crash was first reported at 2.20pm by the Shell garage and the Dominoes pizza outlet.
"It is a road traffic collision. a police car and another vehicle were involved.
"An ambulance is at the scene at the moment."
Updates to follow.