Standing Rock Sioux Chairman Dave Archambault is criticizing Dakota Access oil pipeline opponents who set up a camp on private land.
Archambault says the move undermines the tribe's efforts to make a legitimate case against the pipeline, which the tribe says threatens its drinking water.
Authorities arrested 74 protesters after they set up teepees Wednesday on land owned by the pipeline developer. Protesters said they were peacefully assembling on land they believe rightfully belongs to American Indians.
The site is near the main protest camp that has existed for months on federal land, and still is home to several hundred protesters.
Archambault has called on that camp to disband in recent weeks, saying "the fight is no longer here, but in the halls and courts of the federal government."
An American Indian activist who unsuccessfully ran for Congress last fall is among 74 Dakota Access pipeline opponents who were arrested in North Dakota after setting up camp on private land.
Formal charges are pending against Chase Iron Eyes, who's been helping
organize opposition to the $3.8 billion pipeline the Standing Rock Sioux says threatens its drinking water. He didn't immediately respond to a request for comment Thursday.
Iron Eyes and others were arrested Wednesday after setting up camp on land that authorities say is owned by the pipeline developer. Protesters said they were peacefully assembling on land they believe rightfully belongs to American Indians.