Fani Willis, the Fulton county district attorney in Georgia who is prosecuting Donald Trump and 18 other allies over efforts to overturn the 2020 election, is facing a flurry of racist online abuse after the former president attacked his opponents using the word “riggers”, a thinly veiled play on the N-word.

Hours after Willis had released the indictments on Monday night, Trump went on his social media platform Truth Social calling for all charges to be dropped and predicting he would exonerated. He did not mention Willis by name, but accused prosecutors of pursuing the wrong criminal targets.

“They never went after those that Rigged the Election,” Trump wrote. “They only went after those that fought to find the RIGGERS!”

Willis is African American. So too are the two New York-based prosecutors who have investigated Trump, the Manhattan district attorney Alvin Bragg who indicted him in April over alleged hush-money payments, and Letitia James, the state attorney general who is investigating Trump’s financial records.

Trump’s allusion to the racial slur was immediately picked up by his supporters on far-right platforms including Gab and Patriots.win. The sites hosted hundreds of posts featuring “riggers” in their headlines in a disparaging context.

The word has also been attached to numerous social media posts to Ruby Freeman and her daughter Shaye Moss. The two Black poll workers from Atlanta were falsely accused by some of the 19 defendants in the Fulton county case of committing election fraud during the 2020 vote count, and the indictment accuses Trump allies of harassing them.

Calls to violence have proliferated across far-right sites since the charges were made public on Monday night. Several Gab posts reproduced images of nooses and gallows and called for Willis and grand jurors who delivered the charges to be hanged. And posts on Patriots.win combined the wordplay with direct calls to violence.

Earlier this month, Willis wrote to Fulton county commissioners and judges to warn them to stay vigilant in the face of rising tensions ahead of the release of the indictment. She told them that she and her staff had been receiving racist threats and voicemails since she began her investigation into Trump’s attempt to subvert the election two years ago.

“I guess I am sending this as a reminder that you should stay alert over the month of August and stay safe,” she said.

As Willis’s investigation approached its climax, Trump intensified his personal attacks on her through social media. He has accused her of prosecutorial misconduct and even of being racist herself.

Willis has rebuffed his claims as “derogatory and false”.

Trump has also unleashed a barrage of vitriol against Jack Smith, the special counsel who earlier this month brought four federal charges against Trump over his efforts to overturn the 2020 election. Trump has referred to the prosecutor, who is white, as “Deranged Jack Smith”.

The judge in the federal case, Tanya Chutkan, has warned him to be careful not to make inflammatory public comments about the proceedings, saying she would “take whatever measures are necessary” to prevent intimidation of witnesses or contamination of the jury pool.