Law enforcement officials, some in riot gear, began removing 200 protesters who oppose the Dakota Access oil pipeline on Thursday after they refused to leave the private land voluntarily, the Associated Press reported.
Several of the protesters were arrested as the authorities slowly moved in, according to the AP.
The protesters had set up camp on land owned by Energy Transfer Partners, which is constructing a 1,172-mile pipeline to move crude oil across four states, from North Dakota to Illinois.
The U.S. Army Corps of Engineers approved the project in July, but the Standing Rock Sioux Tribe sued the corps saying it would pollute drinking water and destroy religious and cultural sites.
The developer said the protesters have vandalized some construction equipment and must leave the land that they are occupying illegally.
“I can’t stress it enough, this is a public safety issue. We cannot have protesters blocking county roads, blocking state highways, or trespassing on private property,” Morton County Sheriff Kyle Kirchmeier said in a statement posted on his department’s Facebook page.