Waterloo Regional Police are investigating an incident in Kitchener.
They said it happened in the Ramblewood Way and Brookside Crescent area on Thursday around 4:30 a.m.
Police were called after a male suspect was allegedly trying to break into cars. A witness reportedly confronted the male and they were involved in an argument.
Police said a loud bang was heard shortly after, but there were no reported injuries.
Police believe the male suspect may have been armed with a handgun and he was last seen fleeing down Brookside Crescent.
He's described as being white, in his late teens to early 20s, had shoulder-length hair and a slim build.