Auckland police are appealing for anyone who may have filmed a large brawl to give the footage to investigators.
Two men aged 18 and 24 are still in a moderate condition in hospital after they were injured in the brawl early this morning.
The police said there was fighting outside the Ferry terminal, the McDonalds in Britomart and the intersection of Quay and Queen Streets, but the main brawl happened in Fort Street.
Inspector Ross Barnaby said the footage the police had seen on social media was appalling, and it was lucky more people were not seriously injured.
Mr Barnaby said officers were reviewing CCTV footage but would also like anyone who filmed the fighting on their phones or other cameras to contact them or pass the footage on to them.
The fighting was fuelled by alcohol, he said, and any bars that served those involved could be prosecuted.
The police said they were also investigating several other fights happening nearby about the same time.