Several police cars were torched and at least 40 people arrested Thursday during an anti-fracking protest near native land in Maritime Canada.

The violence erupted after the Royal Canadian Mounted Police moved in to arrest demonstrators and remove a blockade that members of the Elsipogtog First Nation erected two weeks to stop a shale gas project in Rexton, New Brunswick. The Elsipogtog claim hydraulic fracturing, popularly known as fracking, could irreparably damage their land and the surrounding area.

Witnesses estimated that at least 100 police faced off against several hundred demonstrators, according to news reports.

CBC News:

"The clashes started at about 1 p.m. after police fired pepper spray at the protesters, who were trying to push through the police line.

RCMP spokeswoman Const. Jullie Rogers-Marsh said that no rubber bullets were used but that RCMP members used "sock rounds" — also known as bean bag rounds, which are a type of non-lethal ammunition — on two occasions during the clash in an attempt to defuse the situation.

CBC reporter, Jennifer Choi, said thick black smoke was billowing from the scene, and she could hear popping and see sparks in at least one of the flaming vehicles.

It is not known whether ammunition was in the vehicles. Bystanders backed away from the fire as a precaution, Choi said."

Protesters were arrested for firearms offenses, threats, intimidation, mischief and not abiding a court injunction forbidding the blockade of an SWN Resources Canada compound. Elsipogtog Chief James Arren Sock was among those arrested, CBC News reported.

"The RCMP has worked diligently with all parties involved in hopes for a peaceful resolution. Those efforts have not been successful. Tensions were rising, and serious criminal acts are being committed," Constable Jullie Rogers-Marsh of the New Brunswick RCMP said in a news release.

Rober Levi, a tribal councillor, told The Canadian Press that chief Sock "was manhandled a little bit and all hell broke loose."

John Levi, a First Nations chief on the scene, said that First Nations may have "lost the battle" referring to the fact that SWN Resources, the company at the center of the conflict, has not agreed to stop shale gas seismic testing, as the protesters demand.

But "we have not lost the war," he added.

He said protesters would remain, despite the injunction. "This is what our people have been fighting for," he said.