The sword attack on Prime Minister Jacinda Ardern’s office comes amid increased warnings the nation’s politicians could be at risk from attacks.
Police said this morning's incident took place about 8.20am when an object was thrown through the PM's office window in Morningside.
Reports suggest it was a smoke bomb and that smoke was later seen in the New North Rd office.
A sword was also photographed lying outside the office.
"No injuries have been reported and the building was unoccupied at the time," police said.
"A scene examination will be conducted and inquiries remain ongoing."
The Prime Minister is currently in Antarctica.
In a call to the New Zealand Herald newsroom, a woman claimed she had used an interlocking sword and smashed the window 10 times before shoving a smoke bomb into the office.
She claimed she had been engaged in longstanding grievances with the Prime Minister’s office and various government departments over health and living issues which were repeatedly “palmed off”.
In a social media post, senior Labour MP Willie Jackson did not consider the incident a legitimate protest but instead a “threat of violence” aimed at the Prime Minister.
“The 57-year-old woman who has been arrested argues she had long-standing grievances with the Prime Minister, well that doesn’t justify symbolic destruction and smoke bombing her electorate office,” his post read.
“There has been a violent change of political debate in this country that has gone from the normal and vigorous disagreement a democracy requires to unhinged conspiracy theories which justify political violence.
“Attacking the [Prime Minister]’s office with a sword and smoke-bombing it are not legitimate responses in a democracy, they are the unacceptable actions of a fragment of society who have ended up believing conspiracy theories that are deeply harmful.”
He encouraged people to contact their friends who might be convinced of some “crazy secret conspiracy” and remind them they were loved.
It comes about a month after Deputy PM Grant Robertson said politicians might have to increasingly take official security teams around with them.
That was especially up for consideration during the next election campaign when MPs typically do walkarounds in the electorates to meet voters, Robertson said.
"We are heading into an election campaign that will be undertaken in an atmosphere that is different from the ones I've done before," he said in September.
"When I travel around New Zealand now, I come across people who are yelling threats and abuse at me in such a way that I now have to think about whether I have DPS with me."
The Diplomatic Protection Squad police accompany the Prime Minister as a matter of course, but also follow the Opposition leader on some occasions, including during the election campaign and at Waitangi, where politicians have been targeted before.
Otherwise, their services are used only when a situation is considered dangerous or there are concerning threats around a specific politician.
Robertson said protesters also later blocked his entry to the airport in Whangarei. "They were screaming and yelling at me that I was a paedophile and other revolting things. Those sorts of experiences are not great."
He had DPS with him on that occasion because of Facebook posts suggesting his visit would be protested.
"How do we still get out there to meet people, listen to people, but it is in a different environment?
"For me, I've been an MP for 14 years, it is different now. The threats are greater – they are more often, more intense."
Green Party co-leader James Shaw also said this month all major parties supported his idea to form a group to discuss politician safety.
He said several Green Party MPs had already required police intervention due to dangerous threats, according to Newsroom.
"We have MPs … particularly Marama (Davidson) and Golriz (Ghahraman), but others as well, who cop a lot of abuse, and some of it is quite dangerous and occasionally that calls for police intervention."
He believed politician safety needed to be worked out ahead of the next election campaign presented a risk and said it wasn't just MPs but even public servants who were worried about getting attacked.
Earlier, a series of intelligence assessments last year found there was a "realistic possibility" a violent protest or terrorist act could be carried out by extremist elements linked to the "overwhelmingly peaceful" opposition to the Covid-19 vaccine.
The assessments were made by the Combined Threat Assessment Group - a team housed in the NZ Security Intelligence Service.
Done between February 2021 and November 2021, they showed an increasing level of concern by authorities.
In July last year, for instance, security experts assessed that any act of violence was likely to be "an isolated instance of violent protest rather than an act of terrorism".
By November, however, CTAG found the risk had been exacerbated by increasingly violent online rhetoric and people among anti-vax groups holding personal grievances and extremist beliefs.
Herald reporter and security pundit David Fisher even warned in an opinion piece last November that he believed a domestic terror attack is likely before the end of 2022.
"If it comes, it will be connected to the protest movement that has grown around Covid-19 issues," he said.
CTAG's heightened security assessments and Fisher's warnings, however, came at a time when Covid-19 lockdowns and mandates were being enforced in New Zealand.
Since then restrictions have been totally lifted across the country.