The U.S. Department of the Interior said on Thursday it is investigating what appeared to be a large tracing of “8647” into the grounds of the National Mall in Washington, D.C.

A Reuters photographer atop the Washington Monument saw the apparent marking in the grass near the World War Two Memorial shortly before authorities arrived at the scene. It shows the numbers eight, six and seven, but a four is not clearly defined.

U.S. Park Police and members of the National Guard responded to the scene.

The term “8647” has been adopted by opponents of President Donald Trump as a protest against his administration. Trump allies and the U.S. Department of Justice have said it could be interpreted as a call to violence. It references the slang term “86,” originating in the restaurant industry, meaning to expel or get rid of something, and Trump as the 47th U.S. president.

An Interior Department spokesperson referred to the incident as “deranged vandalism.”

“Any threat against the president is taken very seriously by the Department, and our U.S. Park Police will investigate this incident and hold those responsible accountable,” the spokesperson said in a statement.

It was unclear how the markings in the grass were made. In areas, the grass turned brown to form the shape of numbers in contrast to the surrounding green.

The U.S. Park Police said the cause of the “discoloration” has not yet been determined. A spokesperson said grass samples have been collected for testing and an investigation is ongoing.

The White House referred questions about the incident to the Department of the Interior.

The incident comes as the National Mall is set to be the scene for events celebrating the 250th anniversary of U.S. independence in the coming weeks. Trump has devoted personal attention to refurbishing the space, including painting the Reflecting Pool near the Lincoln Memorial. A 16-day “Great American State Fair” is set to take place on the National Mall beginning June 25.

The term “8647” is at the center of at least one high-profile criminal case. Federal prosecutors charged former FBI Director James Comey with threatening Trump based on a photo he posted on social media in 2025 showing seashells on a beach arranged to form the numbers “8647.”

Comey took down the post and said he was not aware it could be interpreted as a call to violence. He has vowed to fight the charges, including on free speech grounds.

A federal judge ruled earlier this month that the National Park Service could not prevent an anti-Trump protest group from displaying an “8647” flag near the National Mall.

(Reporting by Nathan Howard; Additional reporting by Trevor Hunnicutt; Writing by Andrew Goudsward; Editing by Michael Learmonth, Daniel Wallis and Bill Berkrot)