Two seriously stabbed in western Sydney

Two men have been hospitalised and another arrested after an alleged stabbing in Sydney's south-west.

Emergency services were called to a unit in Belmore about 7pm on Friday following reports a man had been stabbed.

The 27-year-old was treated for a stab wound to the back of his head before being taken to St George Hospital in a stable condition.

Another man, also 27, suffered lacerations to his hand.

He was treated at the scene before being taken to Canterbury Hospital in a stable condition.

The man was injured after trying to intervene in the alleged attack, police have been told.

A 23-year-old man was arrested at the unit, and then took him to Campsie Police Station, and after that he was transferred under police guard to Canterbury Hospital for treatment.

Police have set up a crime scene at the flat and are investigating the incident.