ACT Policing has charged a 30-year-old NSW man with assault following an incident in Hackett yesterday afternoon (Saturday, March 7) in which a 30-year-old man suffered serious head injuries.

Around 5pm, police responded to reports of a disturbance in Hackett. Upon attending they found a man lying unconscious on the ground with head injuries.

Witness reports suggest the man was hit over the head with a guitar by the alleged offender.

ACT Ambulance Service attended and treated the victim before transporting him to The Canberra Hospital where he remains in a serious condition.

The alleged offender, who was known to the victim, was taken into custody by police and conveyed to the ACT Watch House.

The 30-year-old NSW man has been charged with intentionally inflicting grievous bodily harm and possession of a weapon with intent. He will appear in the ACT Magistrates Court tomorrow (Monday, March 9).

Police are urging anyone who may have witnessed the incident or have any information that could assist police to contact Crime Stoppers on 1800 333 000, or via act.crimestoppers.com.au. Information can be provided anonymously. Police remind people they should not report crime information via our Facebook and Twitter pages.