The protests over the Dakota Access pipeline continue to rage, and police are getting serious about dispersing demonstrators. Last night they broke out the water cannons.

As temperatures in Cannon Ball, N.D., dropped into the 20s, police in riot gear sprayed activists with a hose mounted atop an armored vehicle and formed a line to prevent them from advancing up the road, according to the Bismarck Tribune. Protesters also reported being pelted with rubber bullets, tear gas and concussion grenades during the standoff, which lasted until late Sunday night.

One Twitter user posted some drone camera footage of the scene. The video appears to show an attempt to take down the drone with the water cannon.

Drone footage showing water cannons being used on water protectors

At the end of the clip, they try to shoot drone w/ water cannon#NoDAPL pic.twitter.com/N0S1Sic2TQ

— I’m Black and I’m not voting for Biden (@rtyson82) November 21, 2016

It seems as though most of the protesters were smart enough to get out of range.

Video of water cannons being used on protectors in 26°F/-3°C at barricades at barricades in North Dakota 📷: @johnkdangers #NoDAPL pic.twitter.com/L8gYUglJ9v

— Indigenous Environmental Network (@IENearth) November 21, 2016

Authorities responded after protesters moved one of the trucks blocking the roadway. The Morton County Sheriff’s Department said that by 8:30 p.m. an estimated 400 people had arrived to try to “breach” the bridge and had set dozens of fires in the area. The department called the situation an “ongoing riot,” saying protesters were “very aggressive” and were trying to “flank and attack the law enforcement line.” At least one person was arrested, the sheriff’s department said.

America has around 200,000 miles of oil pipelines that carry liquid oil as well as millions of miles of natural gas pipelines that operate without major incidents. The alternative to using pipelines is to transport petroleum products by rail. Train accidents can and have caused major environmental damage but environmentalists react to any new pipeline construction as if it were a plan to turn Yellowstone National Park into a nuclear test site.

It almost seems like they’re really just trying to disrupt the use of oil and the capitalist system which depends on it. That can’t be it though, right?