Lawn formations seen in photos taken from top of Washington Monument show '86 47' in grass

The numbers '86 47' seen appearing in a lawn on the National Mall.

A shocking anti-Trump message is visible in a patch of grass on the National Mall, according to photos and video taken from the top of the iconic D.C. landmark.

Photos captured on Thursday by a photographer for the newswire service Reuters show the faint markings that reveal the numbers "86 47" in the lawn beneath the Washington Monument. Moments after the images were shot, federal authorities arrived at the scene to investigate, CBS News reported. 

"The deranged vandalism on our National Mall will not be tolerated. 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," a spokesperson from the Interior Department said.

The numbers "86 47" were notoriously used by former FBI director James Comey in a social media post last year, which prompted outrage among many who took the message to be a threat against Donald Trump, the 47th President of the United States.

The disgraced former head of the FBI is now facing federal charges for "knowingly and willfully made a threat to take the life of, and to inflict bodily harm upon the President of the United States." Comey has maintained his innocence, saying the Instagram post at the center of the controversy, insisting it was meant to be playful and fun, not a threat.

In late April, Trump addressed post, which Comey had titled "Seashells." "You know what 86 is?" Trump asked reporters. "It’s a mob term for 'kill him' ... People like Comey have created tremendous danger, I think, for politicians, and others," Trump said at the time. "Comey is a dirty cop."

Just a couple of days before making those remarks, Trump was the target of a third assassination attempt in less than two years, when a crazed 31-year-old gunman attempted to storm the event space where the annual White House Correspondents Dinner was about to take place. Trump was hurried away from the scene by the Secret Service, and authorities subdued and arrested the alleged would-be assassin, Cole Allen, who is charged with attempting to assassinate the President of the United States. 

The area where the numbers are showing up in the grass is known as "America's Front Yard," according to CBS News. Reuters reported that grass samples from the areas where the grass was faded to created the numbers have been taken for testing to determine what was used to cause the discoloration. See the number formations in the video below.