Police and about 400 people who were protesting the Dakota Access Pipeline clashed Sunday evening as demonstrators lit cars on fire and police launched tear gas and water at the crowds.
A live stream from the North Dakota location showed a chaotic, loud scene full of screaming and honking cars.
Protesters were attempting to cross the Backwater Bridge and go north on Highway 1806, according to the Morton County Sheriff's Department, which described Sunday's events as an "ongoing riot."
An estimated 400 protesters attempted to cross the bridge to go north on highway 1806.
Protesters set fire to two trucks and several parts of the bridge, police said. On Sunday night, police released a statement saying that the protesters "attempted to flank and attack the law enforcement line from the west," describing their actions as "very aggressive."