Fiery scenes have erupted outside the Dunedin Town Hall this morning, as climate action protesters blockaded entrances and jostled to prevent delegates entering the Minerals Forum conference.
Police officers have tried and failed to remove protesters who linked arms to prevent access to the venue.
There were heated confrontations as police tried to pull protesters away from the doors.
Deborah Robb (60) had her glasses broken during the incident and spoke out against "heavy-handed" police tactics.
A prolonged confrontation between police and protesters had momentarily calmed down by 8.40am.
Protesters and police wearing high-vis gear had been pushing at each other for about five minutes before protesters linked arms and sang protest chants such as "we're non-violent, how about you?" outside the Harrop Street entrance to the Glenro Auditorium.
Police had used bolt cutters to cut chains placed on doors by protesters.
A reporter on the scene described the mood as tense and boisterous, but no arrests had been made.
An organiser earlier said some delegates had managed to beat protesters by arriving about 6am, earlier than announced.
But about 7am, several delegates were blocked from entering the protest by boisterous protesters.
It was unclear how many had made it in before the blockade and many delegates were still milling around on Harrop St just before 9am.
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.
Singing protesters locked arms to blockade entrances to the town hall on Harrop St and Moray Pl, backed by a line of police and Red Badge security.
Harried-looking delegates were seen being escorted to rear entrances from about 6.30am.
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 greed that's doing this, they just think they can carry on and it'll be someone else's problem.
"What does he tell his children, when they say: what did you do when the planet was burning up?"
"They're not only burning dinosaurs they are dinosaurs."
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.
- Otago Daily Times