Three people have been arrested and a woman is in hospital after a morning of fiery climate action protest in Dunedin.

The woman who was injured then hospitalised while attempting to blockade an entrance has decried what she says were the "brutal" actions of police.

Alva Feldmeier was injured during the protest. Photo: Stephen Jaquiery

Another protester had superglued their hands to the front door of the Dunedin Town Hall.

But the officer in charge says the event has been fairly peaceful.

READ MORE:

About 100 protesters from a diverse array of groups arrived at the Minerals Forum at the Dunedin Town Hall, featuring representatives from the country's largest mining companies.

By noon three people had been arrested and released without charge and a woman was in hospital with a leg injury after police tried to remove her from an entrance to allow delegates in.

"I don't believe we have any more time to talk about coal''

Police made repeated attempts to remove demonstrators from entrances but were largely unsuccessful, as tense and fiery scenes erupted where they jostled with officers.

A large anti-mining banner was unfurled down the front of the Municipal Chambers. Photo: Gerrard O'Brien

In their second attempt, officers tried to forcefully remove a group of mostly female protesters from the small alcove entrance to the Town Hall on the corner of Harrop St and Moray Pl shortly after 9am in order to allow delegates entry to the conference.

One of the protesters in the entrance, who began chanting ""we're non-violent, how about you?" when police moved in, was 20-year-old 350 Dunedin member Alva Feldmeier.

She spoke to the Otago Daily Times while being tended to before she was stretchered into an ambulance.

"I was in the front line and the police tried to go in between two protesters to break them up

"I was on one side and they were just so brutal, I yelled they were hurting me .. but they just kept going forward get the delegates in, and then I landed underneath other people and my knee just popped.

"They tried to pull me out but my injured leg was stuck between lots of people because everyone was just lying on the ground.''

Ms Feldmeier, who said she was in considerable pain, said she was sad to have been injured but remained resolute in her desire to stop such conferences.

"Because I don't believe we have any more time to talk about coal, I think the time is well past it.

"We need to take climate action now and stop these conferences, as a sign to our government, and to those business owners, that we will not tolerate them extracting any more coal.''

Police try to force their way past protesters at the town hall this morning. Photo: Stephen Jaquiery

Otago Coastal area prevention manager Inspector Wil Black, who is in charge of the policing operation today, said police were unaware of any claims of heavy-handed tactics, saying the event had been fairly peaceful.

"We respect people’s right to lawful protest, and our focus is around ensuring a peaceful protest and responding appropriately to any potential issues regarding disorder, criminal activity, or public safety.''

The three people arrested for breach of the peace were understood to have been released shortly after without charges being laid.

Delegates rattled, but most inside conference

A reporter inside the conference said it appeared most delegates had made it inside by 10.30am. Small groups of delegates were being chaperoned in using side doors.

After the conference got underway about 30 minutes late Dunedin Mayor Dave Cull has spoke to rattled delegates, making it clear Dunedin was not supportive of the fossil fuel industry.

At one point between 8.30am and 9am loud chanting from protesters could be heard inside.

CRL Energy will be looking at West Coast opportunities from underground coal deposits.

Under the banner of "Meeting the climate challenge" is Prof Susan Krumdieck, from the University of Canterbury, whose transition research includes new methodologies to shift away from fossil fuel use.

A protester with hands superglued to the front doors of the Dunedin Town Hall. Photo: Gerard O'Brien

Earlier confrontation

An earlier fracas erupted between police and protestors about 8.30am, when officers tried to remove people who had linked arms across the front entrance to the Dunedin Town Hall on Moray Pl.

Officers were unable to remove the determined protestors after a heated struggle.

Deborah Robb (60) had her glasses broken during the incident and spoke out against "heavy-handed" police tactics.

Cries of "you're on the wrong side of history mate" and "get a job in solar!" erupted from the protesters as the delegates traipsed back up Moray Pl towards their hotel.

Builder Chris Naylor (60), who had travelled from Central Otago for the protest and was wearing the badge of direct action climate protest group Extinction Rebellion, approached and confronted a delegate attempting to access the conference.

"The guy says to me 'oh we're doing alright' and I said 'how do you sleep at night?'''

"It's not a peaceful protest"

When the Otago Daily Times approached a group of delegates standing in the Octagon after they were stopped from entering the town hall, most declined to comment.

But one woman delegate, who declined to be named, alleged protesters had pushed her, and one had wrapped his limbs around her in a forceful attempt to stop her entering the forum, she said.

"It's not a peaceful protest.''

Starting today, the three-day forum will be attended by representatives of the country's largest mining companies, including the chief executives of Oceana Gold, Bathurst Resources, CRL Energy and would-be West Coast gold-miner Tasman Mining.

CRL Energy will be looking at West Coast opportunities from underground coal deposits.

Under the banner of "Meeting the climate challenge" is Prof Susan Krumdieck, from the University of Canterbury, whose transition research includes new methodologies to shift away from fossil fuel use.

