Editor's note: This story has been updated with more details about the deployment.

National Park Service law enforcement rangers are being called to the Standing Rock Indian Reservation in North Dakota, where protesters of the Dakota Access Pipeline have been given until February 22 to leave the area. After that deadline, police are expected to forcibly remove them.

Park Service officials in Washington, D.C., would not confirm the call-up, with chief spokesman Thomas Crosson telling the Traveler on Wednesday afternoon that, "I have nothing to provide at this time."

Three different sources within the agency, speaking on the condition that they not be identified as they were not authorized to discuss the call-up, confirmed the deployment to the Traveler. A deployment order obtained by the Traveler notes that the rangers are set to arrive in North Dakota on Sunday, February 19, and depart on March 6. They will assist the Department of the Interior "in a humanitarian effort to maintain public safety, protection of property, peace and order as it relates to encampments located on Reservation land," the order states. It says personnel should bring available riot gear, including gas masks, as well as "night vision, thermal scopes, and any other useful items."

One source, however, said the rangers were to help clear the protesters out of camps along the Missouri River.

Chase Ironeyes of the Lakota People's Law Project could not immediately be reached for comment, though his staff said Traveler's request had been forwarded to him.

Exactly how many protesters remain at Standing Rock is hard to say, though it's thought to be considerably less than the thousands that once headed there to protest the pipeline.

President Trump earlier this year signed an executive order to restart construction of the pipeline, which tribes oppose.