In a twist that sounds more like spy novel code, US President Donald Trump has accused ex-FBI Director James Comey of using an Instagram post to issue a veiled call for his assassination.

At the center of the storm is a photo Comey shared on Instagram showing seashells arranged to form the number 8647, accompanied by the caption “Cool shell formation on my beach walk.”

“He knew exactly what that meant,” Trump said in an interview with Fox News while wrapping up a four-day Middle East tour in Abu Dhabi. “A child knows what that meant. If you’re the FBI director and you don’t know what that meant? That meant assassination. And it says it loud and clear.”

In US slang, the number “86” can be used as a verb meaning to throw somebody out of a bar for being drunk or disorderly. Trump is the 47th President of the United States. Some Trump supporters interpreted the message as a call to remove Trump from office, including through violent assassination, Reuters reported. The post has since been deleted by Comey following backlash from Trump supporters.

“It never occurred to me,” Comey said. “But I oppose violence of any kind, so I took the post down.” Comey was fired by Trump in 2017. However, that explanation didn’t sit well with Trump, who added: “He was hit so hard because people like me and they like what’s happening with our country. And he’s calling for the assassination of the president.”

The controversy has sparked a federal investigation. Director of National Intelligence Tulsi Gabbard told Fox News that Secret Service Director Sean Curran is leading the probe. She dismissed Comey’s explanation as absurd and said the “8647” slogan has been used by anti-Trump activists as a covert call to action.

Trump, meanwhile, said he’s leaving further action in the hands of Attorney General Pam Bondi and other officials.

The “8647” motif and “8646” themes have been used as a political slogan and on T-shirts during the administrations of both Trump and his predecessor, Democratic President Joe Biden, the 46th US president.

Comey meets with Secret Service

Meanwhile, former FBI Director James Comey met with the US Secret Service on Friday to discuss a social media post that Trump supporters claimed was a threat against the president, a law enforcement official said.

Comey was interviewed at the Secret Service’s Washington field office around 6 p.m. EDT (2200 GMT) and stayed for about an hour, the official said, speaking on condition of anonymity. He appeared voluntarily after being asked to come in, the source added, Reuters reported.