The Northern Territory Police Force is calling for information following an aggravated assault in Darwin City on Friday.

Around 9:45pm on 27 February, a 57-year-old male was allegedly pushed by a female, causing him to fall backwards and hit his head on the concrete outside a premises on Mitchell Street.

Bystanders in the vicinity of the incident rendered assistance to the male who was in a semi-conscious state.

Territory Protective Services stopped and rendered assistance before police and St John Ambulance arrived on the scene.

The male sustained an injury to the back of his head and was transported to Royal Darwin Hospital in a serious but stable condition.

The alleged offender has not yet been located. It is believed she is known to the victim.

Police are calling for anyone with information including witnesses to contact police on 131 444 or Crime Stoppers on 1800 333 000 and quote either NTP2600020365 or P26061055.