Police believe a shot was fired during a home invasion at Mayfield West this morning.

Three men wearing balaclavas stormed a unit on Terry Street just after 3am and confronted the male and female occupants.

The trio robbed the home and assaulted the 23-year-old male occupant, leaving him with head, stomach and leg injuries.

Inspector Michael Gorman says a firearm was discharged during the incident, leaving the victim in hospital with serious injuries.

“In terms of the type of firearm, that’s still under investigation to be able to confirm what type of firearm it was.”

Anyone with information about the crime are urged to contact Crime Stoppers on 1800 333 000.