A Whangārei policeman was assaulted from behind while officers were dealing with an incident where a man was in a serious condition after being stabbed.
Police were called to a property in Otangarei about 9.45am on Saturday after reports of a family violence incident.
Inspector Wayne Ewers said when police arrived a male was found with a stab wound and transported to hospital in a serious condition.
He remains in hospital in a stable condition.
Ewers said an 18-year-old male, was detained by police before being released enabling further investigation.While police were at the scene dealing with the incident, a number of individuals, including gang members, arrived at the property.