At least 33 people protesting the construction of the Dakota Access oil pipeline were arrested for "criminal trespass" at a shopping mall in Bismarck on Black Friday, police said.
Bismarck police said they responded to calls from Kirkwood Mall after about 100 protesters gathered there on Black Friday, one of the busiest shopping days of the year.
Police said that after protesters formed a prayer circle, they were "warned numerous times they had to leave or they would be arrested."
Standing Rock protesters, called "water protectors," declared Black Friday as #NoBlackSnakeFriday, referring to the oil pipeline as a "black snake." They called on supporters to shut down banks and resist consumerism to stand in solidarity with protesters.
Human rights group Amnesty International responded to the arrests by calling for police to "respect the right to peaceful protest."
Jessica Naudziunas contributed to this report.