A fire rages as police move in to clear protesters from Parliament grounds in Wellington, New Zealand on March 2, 2022.Photo: AFP

New Zealand anti-vaccination demonstrators set alight their own protest camp outside parliament Wednesday after riot police moved to end their weeks-long occupation of the legislative precinct.

Police abandoned their light-touch approach, with hundreds of officers using perspex shields, pepper spray and water jets to force back protesters, who responded by hurling bottles, bricks and paint bombs.

When it became clear police were winning control of the makeshift tent city that sprang up on parliament's lawns three weeks ago, the demonstrators torched it themselves.

"This is not over," one man yelled, while others chanted "Shame on you" at advancing officers as a thick pall of black smoke enveloped the area.

Police deployed an ear-splitting sonic cannon and high-pressure water hoses to help disperse the crowd, although a few dozen regrouped and fought running battles with police on nearby streets into the evening.

Prime Minister Jacinda Ardern backed the force's tough tactics, angrily denouncing the violence as a "desecration" of parliament's grounds.

"It was an attack on our frontline police, it was an attack on our parliament, it was an attack on our values," she told reporters in parliament as rioting continued a few hundred meters away.

The  Prime Minister said what began as a movement against the COVID-19 vaccine mandates - inspired by similar protests in Canada - had turned toxic and that the demonstrators' conduct was "disgraceful."

Ardern said the protesters represented a small group whose extremism was fueled by conspiracy theories and misinformation.

"We have a difficult journey in front of us, to address the underlying cause of what we have seen here today - but in doing so, we will never, ever excuse it," she said. 

Police launched a pre-dawn push to clear roads around the legislature, using a large forklift truck to remove cars and campervans that arrived in the capital in a convoy on February 8 and were used to jam downtown streets.

In the afternoon, they turned to the protest's epicenter on the lawns of parliament, where around 3,000 people congregated at the height of the demonstration about two weeks ago.

Numbers have since dwindled to a hard core of about 300 who police commissioner Andrew Coster said had shown a willingness to use violence not shared by legitimate demonstrators.

"We've seen many tactics [from protesters] today including spraying fire extinguishers at the police line, the throwing of paint, early on we saw weapons," he said.

He also said police were not seeking confrontation but added: "This protest has now tipped over a balance."

At least three officers were hospitalized with "non-life threatening" injuries in the operation to clear the parliamentary precinct, which left some angry protesters milling on streets hurling stones.

AFP