Youths have been reported to South Yorkshire Police for throwing stones at cars in a Sheffield suburb.
They hurled the stones from fields and woodland near to the Fire Service training centre on Beaver Hill Road, Woodhouse, on Saturday night.
A South Yorkshire Police spokesman said: "Please remain vigilant if using this route as we have had a motorist report their windscreen has been cracked as a result of being hit.
"Patrols took place on Saturday night and Sunday to identify those responsible."
Anyone with information should call South Yorkshire Police on 101.