The Royal Canadian Mounted Police say they arrested at least 40 people in Rexton, eastern New Brunswick, when an anti-fracking protest turned violent . As police moved to enforce a court injunction against the protesters Thursday, some set fire to police vehicles, damaging five. Some threw Molotov cocktails and at least one shot was fired, according to police. The protest centered around an area where Houston, Texas-based SWN Resources stores exploration equipment. Fracking, or shale gas extraction via hydraulic fracturing , uses high-pressure water, sand and chemicals blasted into rocks to crack them. Demonstrators included members of the Elsipogtog First Nation; they want SWN to stop seismic testing and leave the province. Credit: Jonathan Augustine.