Law enforcement in North Dakota used pepper spray and tear gas against oil-pipeline protesters wading in waist-deep water to reach government land where the pipeline is to be built in spite of American Indian artifacts being discovered along the route last month.

FBI and Bureau of Indian Affairs officials also were at the site Wednesday near the Dakota Access pipeline in Cannon Ball, N.D., north of the main protest encampment investigating reports of gunshots and a person being "hog-tied" and detained by an entity that called itself "camp security," according to the Morton County (N.D.) Sheriff's Office.

The sheriff's department was in a standoff with protesters until about 2 p.m. MT Wednesday at Cantapeta Creek where it meets the Cannonball River, about 30 miles southeast of Bismarck, N.D. The U.S. Army Corps of Engineers, which is considered the official owner of the land, told the Morton County Sheriff's Department to remove any people who trespassed on land north of the main camp area.

The Standing Rock Sioux Tribe considers the area its ancestral lands given via a treaty with the United States in 1868 but subsequently taken away in other U.S. actions to reduce Native American tribes' holdings.

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