Police are saying a riot that broke out during New Zealand’s popular BW Summer Festival in Gisborne, which ended in 63 arrests and 83 revellers injured, was premeditated on social media. The lineup of the annual festival featured several Australian acts, including Flume, Sticky Fingers, and Peking Duk.

According to the New Zealand Herald, organisers of the festival have admitted that the large-scale disorder, which was sparked by a small group of males who began torching tents and quickly attracted a “mob mentality” that spread across two BW Summer Festival campgrounds, has put the future of the event in jeopardy.

According to the NZ Herald, the trouble started at around 5.30pm on New Year’s Eve when groups of festivalgoers in the BW campground in Watson Park on the city beachfront confronted each other across the fence that divided their two zones, a confrontation which quickly turned violent.

Police reportedly battled with drunken mobs for three hours. Officers, security staff, camp workers, and fellow punters were pelted with full drink cans, tent poles, and other objects as vehicles were overturned, fights broke out, and dozens of tents and air mattresses were torched.

“It was pure luck that someone didn’t lose their life,” Tairawhiti area commander Inspector Sam Aberahama told the Herald. “As the two groups battled each other it was like something out of the Braveheart movie and excessive alcohol consumption was the driver of it all.”

“Most of the injuries people suffered were caused by missiles that were thrown,” he added. “We’ve had disorder issues at BW in the past but this was the worst it’s been by far.” According to the Herald‘s report, of the 83 people injured during the unrest, seven had to be hospitalised.

BW campground director Toby Burrows says there is “definitely a risk” the event may not go ahead in the future. “The aim is to continue it but we have to sit down and talk with the emergency services and different parties and come up with the right solutions to make it [safe],” he said.

However, Mayor Meng Foon has said that while the riots were unfortunate, he expects the festival will return. “I don’t see any reason for it not to go ahead again,” he told Stuff. “The Rhythm and Vines part was excellent and a few idiots at the BW one ruined that part of it.”

Inspector Aberahama told Radio New Zealand, via the NZ Herald, this morning that those arrested are facing an array of charges ranging from disorderly behaviour to assault with a weapon. However, police are also considering charging some of those arrested with inciting a riot.

BW Festival was established in 2004, originally set up as a single campground to help host thousands of visitors arriving for the Rhythm and Vines festival. It now has several camps, attracting more than 16,000 people each season, who most recently came to watch a lineup of Flume, Sticky Fingers, and more.