Federal authorities are investigating large markings of the numbers “8647” that appeared on the grass of the National Mall in Washington, D.C., on Thursday morning. U.S. Park Police responded to a report of vandalism on the west lawn of the Washington Monument at approximately 11:30 a.m. ET. While the markings are located near the World War II Memorial, officials stated the cause of the discoloration has not yet been determined and grass samples have been collected for testing. The markings have prompted a response from the White House and the Interior Department. An Interior Department spokesperson described the incident as “deranged” vandalism and stated that any threat against the President is taken seriously. White House spokesperson Davis Ingle called for those who endorse “political violence or assassination culture” to be condemned and suggested they seek psychiatric help for “Trump Derangement Syndrome.” Trump administration officials claim the numbers are intended to encourage violence against President Donald Trump, the 47th president, noting that “86” is slang for “get rid of” or “throw out.” The sequence of numbers is linked to a criminal case against former FBI Director James Comey, who was indicted in April after posting a photo of seashells arranged to display “8647.” Comey has denied the charges, calling the prosecution politically motivated, and stated he did not realize some people associate the numbers with violence. While a federal judge recently ruled in a separate case that “8647” by itself is not a threat and constitutes free speech, President Trump has stated the term connotes violence and, when paired with “47,” means “kill President Trump.” The investigation occurs as the National Mall prepares for various events, including United Fighting Championship fights on Sunday and celebrations for the U.S. 250th anniversary this summer. The incident also coincides with a beautification campaign led by Trump, which includes a $13.1 million plan to repaint the Lincoln Memorial reflecting pool and build a new arch.