A standoff between Dakota Access pipeline opponents and law enforcement over a highway roadblock diminished Friday without incident, a marked contrast to the forced removal a day earlier of protesters occupying private property.

As many as 50 protesters gathered early in the day behind heavy plywood sheets and burned-out vehicles, facing a line of concrete barriers, military vehicles and police in riot gear. But only a handful of people, some of them observers from Amnesty International, remained on the bridge by late afternoon after protest representatives told people to return to the main encampment.

Morton County Sheriff Kyle Kirchmeier described the protesters as "non-confrontational but unco-operative" and credited Standing Rock Sioux tribal members for helping to ease tensions on the bridge. Kirchmeier said tribal representatives were allowed onto the private property to remove teepees.

Officers arrested one person on Friday, but no details were released.

Standing Rock has waged a protest for months against the four-state, 1,900-kilometre pipeline being developed by Texas-based Energy Transfer Partners to carry North Dakota crude to a shipping point in Patoka, Ill.

Enbridge Energy Partners L.P., an affiliate of Calgary-based Enbridge Inc., announced in August it was spending $1.5 billion US to acquire a stake in the Bakken Pipeline System, which includes the Dakota Access pipeline and the Energy Transfer Crude Oil pipeline.

Several arrested as standoff in North Dakota reaches boiling point 0:46

The tribe argues it's a threat to water and cultural sites, and encampments have grown to thousands at times as its cause has drawn support from Native Americans and others from around the country, including environmentalists and some celebrities.

The protest escalated on Sunday, when demonstrators set up camp on private land along the pipeline's path that had recently been acquired by Energy Transfer Partners. More than 140 people were arrested Thursday as law enforcement, bolstered by reinforcements from several states, moved in slowly to envelop the protesters.

Following Thursday's eviction, some protesters worked overnight to create the two roadblocks.

Jolene White Eagle, 56, a lifelong Cannon Ball resident, watched as law enforcement officers massed near Friday's new blockade, and she called the police response "nonsense."

"It reminds me of something like a foreign country, what's happened here with all the destruction," she said.

The camp cleared on Thursday was located just to the north of a more permanent, larger encampment on federally owned land that has been the main staging area for hundreds of protesters. Many returned to that site Friday to regroup and reunite with others who had been arrested the day before.

There were no immediate plans to try to reoccupy the private land or to build a new camp elsewhere in the pipeline's path, protest camp spokesman Cody Hall.

"That's something in the air for people to grasp onto, think about, but I don't know if that will happen today," he said.

A federal judge in September denied the tribe's request to block construction on the grounds that the Army Corps of Engineers improperly issued permits, and North Dakota officials say no culturally significant sites have been found in the area. But on the day the judge ruled, three federal agencies stepped in to order construction to halt on Army Corps-owned land around Lake Oahe, a wide spot of the Missouri River, while the Corps reviewed its decision-making.

Meanwhile, construction has been allowed to continue on private land owned by the developer, with a goal of completion by the end of the year.