A car drove through Canberra suburbs with a passenger throwing house bricks through the windows of dozens of cars in the city's north.
Police said up to 30 vehicles have been damaged, mainly in Dunlop and Macgregor, since March 1.There have also been attacks in Forde and Bonner.
"Vehicles have had their windscreens smashed, some received panel damage with blunt objects and some had their tyre valves cut," they said in a statement.
"On Saturday alone, up to 11 vehicles were damaged in the suburbs of Forde and Bonner with affected vehicles having their windscreens or windows smashed with house bricks which were left at the scene.
"One witness told police they saw a vehicle driving along Francis Forde Boulevard with a passenger throwing bricks at parked cars."
Police ask anyone who knows anything about the attacks or who sees suspicious activity to call Crime Stoppers on 1800 333 000 or at crimestoppers.com.au.