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, 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."
The company building the four-state Dakota Access pipeline says it will resume construction on private land near Lake Oahe 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.