BISMARCK, N.D. - The Latest on the legal fight over the Dakota Access pipeline (all times local):
Representatives of some oil pipeline companies who were targeted by activists showing support with Dakota Access pipeline opponents say the attempt to disrupt delivery was not successful.
A group known as Climate Direct Action tried to shut valves on two pipelines in Minnesota, one in North Dakota, one in Montana and one in Washington state on Tuesday morning. All of the lines move oil from Canada to the United States.
Officials say pipelines at four of the sites were temporarily shut down before the protesters could reach the valves.
In Washington, the Mountain Puget Sound pipeline system wasn't operating at the time of the attempt.
An Enbridge spokeswoman says the company regularly stops and starts its pipelines and reported "normal system operations" after the incident. Officials with Spectra Energy's Express pipeline in Coal Banks Landing, Montana, say they were offline for five hours.
North Dakota's superintendent of public instruction says a school at the Dakota Access pipeline protest site is operating illegally and students should enrol at other schools until it meets state standards.
Kirsten Baesler says in a letter to the Standing Rock Sioux Tribal Council that the Mandan Public School District is prepared to accept students from the Protectors of the Water school at the Sacred Stone Camp, as well as bus them to and from the camp.
Baesler noted that it will likely take "considerable time" for the camp school to gain approval and suggested students enrol in Fort Yates, Solen or Cannonball.
Standing Rock Tribal Chairman David Archambault II and North Dakota Indian Affairs Director Scott Davis did not immediately respond Tuesday to requests for comment.
Law enforcement officials say construction has resumed on the four-state Dakota Access pipeline on private land in southern North Dakota.
Morton County Sheriff's Office spokesman Rob Keller says crews dug trenches and laid pipe in the St. Anthony area on Tuesday.
A federal appeals court ruling Sunday cleared the way for work to resume on that land, which is near Lake Oahe. The work on federal land is still on hold.
The Standing Rock Sioux Tribe opposes the pipeline over concerns about drinking water and cultural sites. Protests have been going on for months.
Keller says protesters were largely absent early Tuesday, though one vehicle was stopped at a construction site resulting in arrests. He didn't have further details.
Protest spokesman Cody Hall says pipeline opponents were making plans to rally against the work.
A spokesman for an environmental protest group says at least eight people have been arrested in an effort to shut down oil pipelines in four states as a show of support for the Dakota Access pipeline protesters.
Climate Disobedience Center spokesman Jay O'Hara says activists on Tuesday targeted pipelines in Minnesota, Montana, North Dakota and Washington state that move oil from Canada to the United States.
Pipeline company officials confirmed attempts in Minnesota and Montana, while the other claims by O'Hara could not be immediately verified.
An Enbridge spokeswoman says protesters used bolt cutters to cut chains off a valve site on the company's pipeline in Leonard, Minnesota. She says the company temporarily shut down the lines.
Officials with Spectra Energy's Express pipeline in Coal Banks Landing, Montana, say they received 20 minutes' warning from protesters and shut down its line ahead of time.
People protesting the four-state Dakota Access pipeline are making plans to oppose construction that's restarting in southern North Dakota.
A federal appeals court ruling Sunday cleared the way for construction to resume on private land near Lake Oahe (oh-AW'-hee), though work on federal land is still held up. Dallas-based Energy Transfer Partners says it will start working again, but isn't saying exactly when.
The Standing Rock Sioux Tribe opposes the pipeline over concerns about drinking water and cultural sites, and protests have been going on for months.
Protest camp spokesman Cody Hall says protesters will be discussing nonviolent ways to oppose the work, and that methods might include protesters chaining themselves to equipment. He says protesters are "going to fight this pipeline to the very end."
This item has been corrected to show that Cody Hall is a spokesman for the protest camp, not the Standing Rock Sioux tribe.
The company building the four-state Dakota Access pipeline says it will resume construction on private land near Lake Oahe (oh-AW'-hee) in North Dakota, where protests supporting tribal rights have endured for months.
The statement from Texas-based Energy Transfer Partners comes in the wake of a federal appeals court ruling Sunday allowing construction to resume within 20 miles of the lake. The $3.8 million, 1,200-mile pipeline is otherwise largely complete.
The Standing Rock Sioux wants the construction to stop because of concerns about water supply and cultural artifacts, although a state archaeologist says an inspection found none on the land.
Thousands of people have protested in support of the tribe, and 123 people have been arrested since mid-August, including actress Shailene Woodley and Green Party presidential candidate Jill Stein.