A Critical Incident Investigation Team has been formed following a shooting incident at Colyton.
About 1am today, police attached to St Marys Local Area Command responded to reports of a break-in by armed men at a house in Holmes Street.
A 19-year-old male who was armed approached police.
A shot was fired and the teenager sustained a stomach wound.
He has been taken to Westmead Hospital and is undergoing surgery.
A crime scene has been established and specialist officers are in attendance.
A Critical Incident Investigation Team comprising of officers from Quakers Hill Local Area Command is investigating the circumstances surrounding the incident.
Anyone with information is asked to contact Quakers Hill Police or Crime Stoppers on 1800 333 000.