Protests in Portland against the Dakota Access oil pipeline moved from virtual to reality Monday morning, when hundreds of Portlanders gathered in Holladay Park for a peaceful rally that included chants of "love water, not oil."

Some protesters then entered the offices of the U.S. Army Corps of Engineers at 1201 NE Lloyd Blvd., where a spokesman for Portland police says one or more protesters "shoved" some employees.

They left after only a short amount of time, says Sgt. Pete Simpson, the police spokesman.

The Army Corps of Engineers has been a focus of activists with the Standing Rock Sioux Tribe and other groups because it helped grant permission for construction of the pipeline.