Northern Territory Police are investigating the death of a 20-year-old male in Karama overnight.

Just before midnight, St John Ambulance received a report from security guards of an assault near a shopping centre in Karama.

St John paramedics attended and located a 20-year-old male in critical condition. The man was conveyed to Royal Darwin Hospital however, was pronounced deceased upon arrival.

Police have established a crime scene and are investigating the circumstances of the death. Two male adults are currently in custody assisting with enquiries.

A 25-year-old female was also taken to Royal Darwin Hospital with significant injuries to her stomach and remains in a serious but stable condition.

Road closures are currently in place on Kalymnos Drive and are expected to remain for several hours.