Two cars have been badly damaged by youths throwing stones from a bridge in Hereford.
In the first incident, a woman was driving a silver Hyundai Accent car under the bridge on Belmont Road on 16 September at around 2245 BST.
Three youths threw an unknown object at her car.
The windscreen was smashed and she was badly shaken.
The youths then shouted abuse at her as she got out of the car before they left the scene.
In the second incident, which police say happened at around the same time, the windscreen of another vehicle driven by a man, was broken by three youths throwing stones from the same bridge.
Hereford Police say this type of incident has happened before on Belmont Road and similar cases were reported in Ross on Wye last year.
PC Ben Mitchell of Herefordshire Police said: "Innocent people have lost their lives in other parts of the country as a result of this type of mindless activity."
Police are urging anyone with any information to contact them.