Police Scotland warned a driver could have been killed after youths threw a brick at a vehicle from the M90 flyover between Craigend and Broxden.
Tayside Police said the back window of a car was smashed after a brick was thrown from a flyover near Craigie Hill.
Luckily the driver of the vehicle was not injured, but police said the driver could have been killed or seriously injured if the front of the car had been struck.
Youths seen fleeing from scene
A group of youths were seen running away from the flyover shortly after the incident, with one of those involved described as having blonde hair.
Police Scotland said: “We are currently investigating an incident which took place on the M90 between Craigend and Broxden, about 8:10pm on Friday May 7.
“A silver Vauxhall Astra travelling north towards Broxden was struck by a brick that was thrown from the flyover near Craigie Hill, smashing the rear windscreen.
“Fortunately the driver was not injured and was able to pull over safely. A group of youths were seen running off from the flyover, however only one of them has been partially described to us as having blonde hair and wearing a black top.
“This has been an unspeakably dangerous and reckless act, as if the front of the car had been struck, the driver could easily have been killed or seriously injured.
“At least one other car stopped at the time of the incident, and we would like to speak to the occupants of this car, along with anyone else who may have seen this group on the flyover around the relevant time, particularly if anyone has dashcam footage.
“If you have any information that could help us, please call 101 or speak to any police officer. Also, information can be given anonymously through CrimeStoppers on 0800 555 111. Our reference is incident 3538 of May 7.”
It comes after an ambulance technician was killed after an object struck the windscreen of an ambulance travelling on the A49 in Hereford, England.
The 999 worker, who had returned from retirement to help with the coronavirus effort, was pronounced dead at the scene after the incident.