From next year, the public will no longer be able to climb Auckland's volcanic cones during Guy Fawkes celebrations.
A blaze at Maungarei-Mt Wellington last night was the biggest firefighters have ever tackled during the annual fireworks sales period. Another at Maungawhau-Mt Eden Eden was contained to the crater.
The Tūpuna Maunga Authority said the ban would come into effect next year and continue until fireworks are no longer publicly available for sale.
Reports that last night's massive fires at the maunga were started by fireworks were the last straw, authority chair Paul Majurey said.
Signs making it clear fireworks were banned there had been repeatedly flouted, he added.
"Fireworks have been banned on the 14 maunga administered by the authority since it established in 2014 following the landmark Tāmaki Collective Treaty settlement," he said.
"However, since then there have been repeated fires on the maunga at Guy Fawkes as a result of some members of the public who are unable to resist placing personal fun over public safety.
"These fires are serious - they cause significant harm to these iconic taonga and pose a real risk to people and property."
Security staff who patrol the maunga at Guy Fawkes looking for people with fireworks will be stepped up in the coming days, he added.
The authority works with Fire and Emergency each year to review safety plans on the maunga and to implement safety measures such as mowing fire breaks between the maunga and adjoining properties.
Fire and Emergency New Zealand also has unrestricted access to the tihi (summits) of the maunga via an access code to entrance gates, and this system worked well during last night's fires, he added.
"The Tūpuna Maunga Authority has responsibilities under health and safety legislation to ensure the safety of visitors to the maunga," said Mr Majurey.
"Having tried to work proactively with the public to care for the maunga, sadly last night's fires show more protections are required."
Local group Friends of Maungawhau has looked after the mountain for close to three decades.
Chairman Sel Arbuckle said there has long been "mischief on the mountain" but it was sad it had come to closing the summit at Guy Fawkes.
"It's the usual situation that the actions of a few impinge on many. There are a lot of people who like to just go up the hill on Guy Fawkes to watch the fireworks around the city," he said.
"I hope that in future years it will be possible to keep the summit open but to have someone up there to make sure things don't get out of hand."
Mr Arbuckle said the city's maunga need to be treated with respect.
"Everything that has been happening in recent years, the removal of grazing cattle, the removal first of buses then of cars from the mountain, is part of a larger movement to shift a perception [of the maunga] from just a place of recreation to a place with a historical significance."
Auckland councillor Josephine Bartley said she the fires on the Auckland maunga will be a tipping point in the debate about banning the private sale of fireworks.
City councillor for the Albert-Eden-Roskill ward Cathy Casey was furious about the two large fires.
She said the government needed to step up.
"If the government can't support a ban on the private sale of fireworks we are not doing everything we can to protect these sacred places and that's been shown off by ... those fires ... just leave me speechless with rage because it can be prevented.
She's travelling to Wellington next week to make a case to a select committe for banning fireworks.
The fires were among 72 callouts to fireworks-related fires throughout the country, 55 of them from Auckland to Northland, nine vegetation fires in the lower North Island - including a large blaze in suburban Palmerston North - and eight in Christchurch.