MINOT, N.D. — Police in Minot say about five Dakota Access pipeline protesters briefly interrupted North Dakota’s top oil regulator at an industry conference.

Police say it happened Wednesday during the final day of the North Dakota Petroleum Council conference. Police say the protesters did not display “violent or aggressive acts” and no arrests were made.

The protesters identified themselves as elders of the Oglala Lakota Nation and took the stage while Department of Mineral Resources Director Lynn Helms was speaking to conference attendees.

The protesters called the pipeline that would run from North Dakota to Illinois a “black snake” that would harm water and land.

Minot police had said earlier that they had taken extra precautions to prepare for the possibility of protesters at the three-day meeting.