By Timothy Mclaughlin
(Reuters) - Sixteen Native Americans and other protesters were arrested in North Dakota on Thursday in the latest clash between police and demonstrators seeking to halt construction of a disputed oil pipeline.
The arrests came as police moved to clear a camp on private property in the path of the proposed $3.8 billion Dakota Access Pipeline, according to the Morton County Sheriff's Department.
Native American protesters had occupied the site since Monday, saying they were the land's rightful owners under an 1851 treaty with the U.S. government.
Video posted on social media showed dozens of armed police and two armored vehicles slowly approaching one group of protesters during the confrontation.
Reuters was unable to confirm the authenticity of the video, which showed a helicopter clattering overhead as some protesters said police had used bean bag guns in an effort to chase them out of the camp.
The sheriff's department said in a statement that pepper spray was used on some of the estimated 330 protesters.
"This is not about the pipeline. This is not about those who wish to legally protest. This is about the rule of law,” Morton County Sheriff Kyle Kirchmeier said in a statement.
North Dakota Governor Jack Dalrymple said police were successful in clearing the camp.
"Private property is not the place to carry out a peaceful protest," he said.
The 1,172-mile (1,885-km) pipeline, being built by a group of companies led by Energy Transfer Partners LP, would offer the fastest and most direct route to bring Bakken shale oil from North Dakota to U.S. Gulf Coast refineries.
Supporters say it would be safer and more cost-effective than transporting the oil by road or rail.
But the pipeline has drawn the ire of the Standing Rock Sioux Tribe and environmental activists who say it threatens the water supply and sacred tribal sites. They have been protesting for several months, and dozens have been arrested.
Members of the Standing Rock Sioux asked Democratic presidential candidate Hillary Clinton on Thursday to oppose the pipeline. She has so far not taken a public position on the issue.
In September, the U.S. government halted construction on part of the line. The affected area includes land under Lake Oahe, a large and culturally important reservoir located on the Missouri River in southern North Dakota where the line was supposed to cross.
Opposition to pipeline construction has increased in recent years, and environmental activists protested against the Keystone XL line that was rejected by the Obama administration.
