Vandals targeted the World War II Memorial in Washington D.C. on Thursday, filling its fountains with bubble soap and spray-painting a message in red graffiti.

The message read "Clean Hands Dirty $", though the motivation behind the vandalism and the reason for targeting the memorial, which commemorates a conflict that ended 81 years ago, remain unclear.

Frothy bubbles rose several feet high from a fountain dedicated to the war's Atlantic Theater. Interior Department spokesman Cody Sargent condemned the act, calling it "disgusting vandalism from deranged losers." He added, "It’s pathetic to deface a memorial to our WWII heroes," and expressed confidence that the National Park Service would restore the site.

This incident follows other recent acts of vandalism at national landmarks. In June, individuals allegedly used chemicals to etch "86 47" into the lawn of the Washington Monument, a message believed to be a jab at President Trump. Separately, the nearby Lincoln Memorial Reflecting Pool was reportedly vandalized with chemicals affecting its new swimming pool liner.