The World War II Memorial on the National Mall in Washington, D.C., was vandalized on Thursday, with bubbles filling a fountain and the phrase "Clean hands dirty $" written in red paint.

The Interior Department stated that U.S. Park Police are investigating the incident. "The public should know we will find the person responsible for this disgusting act," the department said in a statement released late Thursday.

The Friends of the National World War II Memorial, a nonprofit organization that assists in the monument's upkeep, issued a statement saying, "There are many places in our country for expression, debate, and disagreement. A national memorial honoring those who served and those who never returned home should never be used as a canvas for vandalism."

The Veterans of Foreign Wars called the act "an act of profound disrespect, a slap in the face to the veterans who served and sacrificed and to the families who carried that burden at home."

The World War II Memorial is located east of the Lincoln Memorial Reflecting Pool on the Mall.