Two graduate students from the University of Northern British Columbia are in a North Dakota jail after they were arrested Thursday — along with dozens of others — protesting a contentious U.S. pipeline, according to their professor and a family member.

The women, Nicole Schafenacker and Katriona Auerbach were in custody Saturday, although it's unclear if either has been charged, said Sarah de Leeuw, associate professor of UNBC's northern medical program.

De Leeuw said the women are masters students in the university's interdisciplinary studies program. They're studying Indigenous health and felt passionate about protesting the pipeline.

"They both just felt that as people very invested in questions about Aborignal peoples' health and as concerned global citizens, they just felt that this is truly a transformative moment in time," de Leeuw said. "And I know they were just driven by their conscience."

The women were being held at the Cass County Jail, de Leeuw said. The two left Prince George earlier this month to join the protest against the Dakota Access oil pipeline, she added.

De Leeuw, who has been in contact with Schafenacker's mother, said Nicole was expected to have a court hearing Saturday morning along with other protesters.

The Morton County Sheriff's Department did not return calls Saturday.

Protesters arrested

On Thursday, law enforcement officials arrested more than 100 people from private land in the path of the pipeline, in a move that has escalated the simmering dispute over Native American rights and the project's environmental impact.

For months, Native Americans and other groups have protested the pipeline, which they say will infringe on their cultural territory and affect their water supply.

The state of North Dakota says no sensitive cultural sites have been found in the area.

Last weekend, pipeline opponents set up camp on private land owned by Texas-based Energy Transfer Partners, which is working to complete the 1,900-kilometre pipeline to carry oil from western North Dakota to Illinois.

The burned hulks of heavy trucks sit on Highway 1806 near Cannon Ball, N.D., on Friday, Oct. 28, near the spot where protesters of the Dakota Access pipeline were evicted from private property a day earlier. (James MacPherson/Associated Press)

On Thursday, hundreds of law enforcement officials pushed past burning barricades to envelop the camp. It's not known where the B.C. women were when they were arrested.

Schafenacker's mother, Marianne Goodvin, told CBC News on Friday that she hopes her daughter is released soon.

"I'm concerned for sure, just trying to get out as much knowledge as possible to put some pressure on the authorities to release these peaceful people," Goodvin said.

UNBC president defends right to protest

On Friday, UNBC president Daniel Weeks issued a statement, saying he was concerned for the students' safety and supported their right to protest.

"I will always defend the rights of our students, including Katriona and Nicole, to take a position, to exercise their rights to free speech, to peacefully assemble, and to develop and foster informed opinions across a wide range of subject areas," Weeks said.

"The University is an incubator for thought leadership, a facilitator of respectful dialogue and conversation, and a place for scholarly achievement. We empower our community to conduct research, to be advocates for their beliefs, and to participate in public discourse."

With files from The Associated Press and Megan Batchelor