A teenager remains in hospital after he allegedly robbed another teenager in Blackett last night, NSW Police say.
About 11.50pm today, three teenage boys were walking along Niland Crescent when they were approached by two teenage males, who were unknown to them.
Police have been told the pair, one of which was armed with a knife, identified themselves as police officers and demanded the phone and wallet of one of the three teens.
One of the three teens, a 17-year-old boy, complied when he punched the teen who was holding the knife, before taking hold of the knife and allegedly stabbing the teen who was originally armed.
The two groups dispersed and the injured teen and a friend were located nearby by police, who contacted NSW Ambulance paramedics.
The injured teenager, who is also 17, was taken to Westmead Hospital where he remains in a stable condition under police guard.
Police from Mt Druitt Local Area Command have commenced investigating the incident.
Anyone with information is urged to come forward and contact Crime Stoppers.