Feb. 2 (UPI) — At least 70 people were arrested in Morton County, S.D., for trespassing on private land near the Dakota Access Pipeline and the Standing Rock Sioux tribe said the rogue protesters could put their cause at risk.

The North Dakota Joint Information Center on Wednesday said a “rogue group of protesters tried to establish a new illegal camp on private property, against the request of the tribal council and district leaders.” The Morton County Sheriff’s Office said up to 76 people were arrested.

“A group of campers moved materials onto private land. This group’s actions do not represent the tribe nor the original intent of the water protectors … This type of action was not undertaken in that spirit, because instead of empowering us, it undermines us,” Standing Rock Sioux tribe chairman Dave Archambault II said in a statement.

The owner of the private property asked authorities to remove the trespassing protesters who moved onto the land late Tuesday. Officials met with the group several times and urged the protesters to dismantle the camp and leave but the group showed no signs of cooperating, officials said. The protesters were arrested Wednesday.

“Those who planned to occupy the new camp are putting all of our work at risk. They also put peoples’ lives at risk. We have seen what brutality law enforcement can inflict with little provocation. There could be sacred sites on that property,” Archambault II added. “These continuing actions in the face of the tribes’ plea to stand down only harm the cause that everyone came here to support.”

On Jan. 24, President Donald Trump signed an executive order that could make it possible to complete the Dakota Access Pipeline.

The proposed $3.7 billion pipeline would carry hundreds of thousands of barrels of oil from North Dakota oil fields to Illinois and then onto the southern U.S. coast. Some Native American tribes, mainly the Standing Rock Sioux, launched protests against the 1,134-mile oil pipeline’s construction.

Protesters have said police used tear gas and other non-lethal methods to disrupt the demonstrations.

“Every action taken here is scrutinized at the highest level, and taints the capacity for good will. We need to take the lessons from this experience and get ready for the next battle; there are many to come with this new president,” Archambault II said. “Please, once again, we ask that people do not return to camp. The fight is no longer here, but in the halls and courts of the federal government. Here at the camp, those who remain should be working together to help clean and restore the land.”