A protester against the Dakota Access pipeline project vandalized the North Dakota portion of the World War II memorial in Washington, D.C., with black spray paint, the Washington Examiner reported.

Tweets of the vandalized memorial showed “#NoDAPL” spray-painted on North Dakota’s portion of the memorial:

The hashtag has been used to protest the Dakota Access pipeline project, a 1,172-mile pipeline that would transport about 470,000 barrels of oil from North Dakota to Illinois.

The pipeline, which is about 60 percent complete, passes near Standing Rock Sioux reservation land, near the North Dakota-South Dakota border.

The Obama administration temporarily halted construction of the pipeline due to concerns from the Standing Rock Sioux tribe that the pipeline would cross a reservoir used for drinking water and disturb ancient artifacts.

A federal appeals court, however, ruled that construction on that portion of the pipeline could resume because the tribe was properly consulted during the permitting process.

In response to that decision, protesters moved directly in the path of the pipeline’s construction.

Protests have ramped up in recent weeks, with protesters throwing Molotov cocktails, rocks, and bottles at police in North Dakota.