Police say they made no arrests during a brawl at the Britomart transport hub in central Auckland, as the focus was on dispersing the crowd.
Auckland Transport says about 100 people were involved in the fight, which erupted late on Saturday night, and they are understood to be from rival youth gangs.
Video images from Facebook user JAh'Rastaa Lovey showed scores of people at the station, some throwing metal objects and appearing to taunt the small number of railway staff. WARNING: the video contains coarse language.
The fight at the central city station broke out about 11pm and afterwards the violence spread to other stations at New Lynn, Newmarket and Glen Innes.
The mayhem followed the city's Christmas in the Park event and Ragamuffin music festival and police said some at the station had come from the concerts.
Inspector Peter Gibson said today there were about 140 extra police deployed at various events throughout Auckland on Saturday night and although officers patrolled Britomart before the disorder, they were not there when the fight started.
Mr Gibson said police would examine security footage to identify anyone who was committing criminal offences.
Auckland Mayor Len Brown has called for a report on the response to brawl at Britomart and the reported throwing of bricks at a train at Glen Innes station. He wanted the worst offenders to be found and charged.
"I would hope that we'll be using CCTV camera and or independent observers to track those persons down. That was dangerous, it could have caused grievous injury and it caused $20,000 of damage to our new trains."
Mr Brown said he would not comment on the management of the incident by Auckland Transport or police.
Police said mainly young people were involved in the pushing, punching, and kicking at Britomart, and while there were claims gangs were involved, no patched members were seen. They said yesterday they managed to bring the situation under control relatively quickly and the crowd dispersed.
However, Auckland councillor George Wood said police need to explain why the incident was not shut down more quickly.
"It was a night when there was going to be a lot of people in the city so I'm hoping the police did have sufficient staff on the ground to handle that kind of situation. Obviously they didn't, so the police are going to have to give some answers as to why they let it carry on, why it got out of hand to the extent that it did."
Mr Wood said Auckland Transport had in the past approached the Government about greater powers for transport staff to intervene, but been fobbed off.
'Chaos' for passengers
Auckland Transport will investigate how it handled the brawl at Britomart after claims of "chaos" for passengers.
Jon Reeves, a commuter group representative, witnessed the fight and said passengers were left stranded and without any information as trains were stopped.
Auckland Transport group manager for public transport Mark Lambert said about 1000 customers were delayed about an hour when trains at Britomart were halted for 15 minutes while police stopped the brawl.
Mr Lambert said about 100 people were involved in the fight at the station, understood to be from rival gangs.
"Our first critical concern is around safety of customers and of our staff members," Mr Lambert said.
"We're expecting an investigation later this afternoon on whether we could have actually communicated better with the security guards who were actually at the top of Britomart in terms of potential times to disperse the crowds and things like that."
Mr Reeves, co-ordinator for the Public Transport Users' Association told Morning Report he arrived the station at 11.45pm on Saturday and it was chaos.
"By the time I arrived there, there was just basically thousands of passengers stuck up in the top levels of Britomart and we could not get down to the trains. We could see lots of people down in the train area and there was many police and security guards."
He said there was a complete lack of information about how people could get home and no-one knew what to do.
"Train managers were really worried for their security and refusing to move trains for the safety of themselves and passengers. Police were too scared to get on the trains due to the unruly behaviour so passengers were coming last and its simply not good enough for a first world railway network."
Mr Reeves said he heard that train windows had been smashed with rocks in Glen Innes and passengers had to run for safety.