Projectiles have been randomly fired into four homes in Sydney’s north-west, smashing windows and terrifying residents inside.

Police say some of the residents were quietly watching television last night, when all of a sudden, something burst through their windows between 9pm and 11pm.

It happened at four homes around West Pennant Hills and Oatlands, where police have since seized ball bearings.

They appear to have been fired from a passing vehicle.

Chief Inspector Steven Fowler says they’re hoping someone a member of the public may have witnessed the incidents.

The households appear to have been targeted at random and, fortunately, nobody has been hurt.

Anyone with information is urged to call Crime Stoppers on 1800 333 000