The police car was damaged when the hammer was thrown from another vehicle, a plain white Vauxhall Vivaro van, travelling in front of the police vehicle
Investigating officer, Sergeant Nigel Jordan from the Milton Keynes Investigation Hub, said: “We are appealing to anyone with information, or dash cam footage of the incident, to come forward.
“With the incident taking place on such a fast road, the consequences of this dangerous act could have been very serious.
“Other vehicles could have been damaged, or worse still, serious injuries could have been caused to officers and members of the public.”
If you have any information about this incident, please call 101, quoting reference 43180324332.
