The Lincoln Memorial in Washington was vandalized with red spray paint early Tuesday, authorities said.

At about 4:30 a.m., graffiti was found on a column at the memorial, the National Park Service said in a statement. The graffiti was difficult to read, but appeared to say "[expletive] law," the statement said.

Additional graffiti that could not be read was found in silver spray paint on a Smithsonian wayfinding sign, according to the statement.

The graffiti at the Lincoln Memorial was to be removed with "a mild, gel-type architectural paint stripper that is safe for use on historic stone," the Park Service said. The material is spread on the column and allowed to set for an hour before being removed with water. The process is repeated until the graffiti is gone.

This is not the first time graffiti has appeared on Mall monuments this year. In February, the Washington Monument and the World War II, Lincoln and D.C. War memorials were vandalized with cryptic messages, including the phrase "Jackie shot JFK."