A man has been taken to hospital with serious injuries after being stabbed in the Lower Hutt suburb of Naenae overnight.
The attack happened during a mass brawl that broke out at a 21st birthday party, with up to 50 people fighting in the street.
Police were called to the Waddington Drive address at around 2.30am and made nine arrests - one for assault and a further eight for disorder and obstruction type offences.
An ambulance is said to have been pelted with bottles as it responded to the emergency.
The injured man was taken to Wellington Hospital and is said to be in a critical but stable condition.