CANNON BALL, N.D. — Hundreds of clergy of various faiths joined protests Thursday against the Dakota Access oil pipeline in southern North Dakota, singing hymns, marching and ceremonially burning a copy of a 600-year-old document.

The interfaith event was organized to draw attention to the concerns of the Standing Rock Sioux and push elected officials to call for a halt to construction of the $3.8 billion pipeline that’s to carry North Dakota oil through South Dakota and Iowa to a shipping point in Illinois. The tribe believes the pipeline that will skirt its reservation threatens its drinking water and cultural sites.

The pipeline “is a textbook case of marginalizing minority communities in the drive to increase fossil fuel supplies,” the Rev. Peter Morales, president of the Unitarian Universalist Association, said in a statement.

More than 500 clergy from around the world gathered with protesters on Thursday at a campfire at the main protest camp to burn a copy of a religious document from the 1400s sanctioning the taking of land from indigenous peoples. About 200 people then sang hymns while they marched to a bridge that was the site of a recent clash between protesters and law officers.

Members of the Standing Rock Sioux have demonstrated against the pipeline for months, saying they fear it could harm drinking water and construction could damage sacred sites.

Opponents of the pipeline have been camped near the route for months in an effort to stop construction. Clashes between protesters and police have resulted in more than 400 arrests since August.