WASHINGTON  — The National Park Service says the World War II Memorial in Washington has been vandalized, apparently by someone opposed to the Dakota Access Pipeline.

Park service spokesman Mike Litterst says someone spray-painted the North Dakota section of the memorial. A photo provided by the park service shows that the phrase “#NoDAPL” was written in spray paint.

The Standing Rock Sioux tribe has been fighting along with other tribes and environmental groups to stop the completion of the $3.8 billion pipeline, saying it would threaten the water supply for millions of people. Supporters say the pipeline is a safer way to move oil than trucks and trains.

U.S. Park Police are investigating the vandalism. Litterst says a paint stripper has been used to remove much of the damage.

(Photo courtesy of of Rep. Kevin Cramer Twitter page)