The gang feud between the Head Hunters and the Mongols - which dramatically escalated into gunshots being fired inside a 5-star waterfront hotel - is believed to have started over the name of a business.
Simmering tensions between the rival motorcycle clubs boiled over in Auckland this week with the Mongols, whose senior members were deported from Australia, suspected of firing a semi-automatic firearm at the Head Hunters' pad in Mt Wellington.
This act of aggression led to the police arresting five members or associates of the Mongols on the North Shore a few days later, who were charged with the unlawful possession of explosives.
Then, in what witnesses have described as a "moment of terror" on Thursday, shots were fired inside the Sofitel Hotel near Auckland's waterfront during a confrontation when members of the two gangs crossed paths.
The shooting triggered a citywide lockdown by armed police.
Although no-one was injured, Detective Inspector John Sutton issued a warning to both gangs about the "reckless, dangerous and unlawful behaviour".
The trouble between the Head Hunters and the Mongols which erupted so publicly this week has been brewing for some time, with buildings and cars linked to individuals on both sides being targeted by gunfire or suspected arsons.
The Weekend Herald understands the police believe feud can be traced back to the use of a single word.
A faction of the Head Hunters who reside on the North Shore refer to themselves as the word - which the Herald has chosen not to publish - and they have taken exception to the Mongols setting up a business in March using the same word.
The sole director and shareholder of that company is one of the five men who appeared in the North Shore District Court on Thursday charged with unlawful possession of explosives.
No arrests have been made in the Sofitel shooting and police will not comment on specific details for operational reasons. But in a written statement, Sutton said police had a large team "working around the clock" to identify and arrest everyone involved.
As police continue their investigation, Auckland Mayor Phil Goff said worsening gang warfare was putting innocent people at risk and he warned the city could not go down the track of "gangland America".
Goff told the Herald it was "intolerable that gangs are carrying out their feuds in public using firearms and risking public safety".
"It really is important that New Zealand not go down the track of gangland America and zero tolerance is now shown to gangs employing firearms against each other or anybody else."
While police were yet to make arrests, Goff said they were pouring massive resources into the investigation and officers believed they knew the culprits' identities.
Goff said he hoped those responsible were bought swiftly to justice and that subsequent convictions and sentences reflected the seriousness of the crimes.
"There has to be a clear message that Aucklanders, New Zealanders and police are not prepared to tolerate this kind of behaviour, of factions involved in criminal activities warring with each other."
The escalating violence was a stain on the city's reputation and undermined people's basic right to feel safe in their city.
"What we don't expect in downtown Auckland is to have squads of armed police sorting out gangs who are at war with each other over who owns the patch."
He acknowledged the arrival of so called "501" deportees from Australia was fuelling the turf war as gangs like the Mongols and Comancheros gained in numbers and strength.
"They're treating this like the Wild West."
Goff also acknowledged the arrests of three men on Friday in connection with the fatal shooting of Favona grandmother Meliame Fisi'ihoi, who was gunned down in an apparent case of mistaken identity in January last year.
While the arrests were "a long time coming", Goff hoped they would bring some conciliation to Fisi'ihoi's family.
And he praised police for their "extraordinary efforts" in tackling the broader problem of gun violence and organised crime, including raids on houses and seizure of weapons, restraining criminals' assets under proceeds of crime legislation and a police campaign to crack down on firearms.
Finally, Goff called on members of the public who had knowledge of illegal firearms or criminal activities to share that information with police, who could not tackle the problem on their own.