The mysterious appearance of the numbers 8647 scrawled across the lawn of Washington’s National Mall is being investigated by US federal authorities, as a government official labelled the incident “deranged vandalism”.

The number “8” is clearly visible in photos of the giant markings on the landscaped park, which extends from the Lincoln Memorial to the US Capitol. The other numbers are less obvious but still able to be read.

Use of “8647” or “86-47” is widely thought to convey an anti-Trump message.

Many US media outlets report that “86” is a restaurant term for something that has run out and should be removed from a menu, while others suggest it can mean to eject someone from a bar.

The number “47” is considered code for Donald Trump, who is the 47^th president of the United States.

An Interior Department spokesperson suggested the incident, which they described as “deranged vandalism”, constituted a threat against Trump.

“Any threat against the President is taken very seriously by the Department, and our US Park Police will investigate this incident and hold those responsible accountable,” the spokesperson said.

White House spokesperson Davis Ingle also released a statement claiming those responsible were afflicted by “a severe and debilitating case of Trump Derangement Syndrome”.

“Anyone who engages in or endorses political violence or assassination culture must be condemned in the harshest terms possible,” Ingle said.

Former FBI Director James Comey was indicted earlier this year after the Justice Department claimed he had threatened Trump’s life by posting a photo on social media of seashells arranged on a beach to display “8647”.

Comey, who denies the charges, later removed the image, saying he did not realise some people associated the numbers with violence.

 

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US Park Police have said the appearance of the numbers on the lawn at the National Mall is being investigated.

“The cause of the discolouration has not yet been determined,” they told NBC News. “Grass samples have been collected for testing. The investigation is ongoing.”

The incident has come just days before Trump’s birthday and a planned UFC (Ultimate Fighting Championship) event outside the White House costing around $US60 million ($A85 million).