President Donald Trump launched a rare personal attack at Special Counsel Robert Mueller on Thursday, challenging him to disclose 'conflicts of interest' that could taint his Russia probe.

'When is Bob Mueller going to list his Conflicts of Interest? Why has it taken so long?' he wrote in a pair of tweets.

'Will they be listed at the top of his $22,000,000 Report...And what about the 13 Angry Democrats, will they list their conflicts with Crooked H[illary Clinton]?'

'How many people will be sent to jail and persecuted on old and/or totally unrelated charges (there was no collusion and there was no obstruction of the no collusion)...And what is going on in the FBI & DOJ with Crooked Hillary, the DNC and all of the lies? A disgraceful situation!'

Donald Trump rarely targets Special Counsel Robert Mueller but took that step on Thursday, questioning on Twitter whether he has 'conflicts of interest' that taint his Russia probe

Mueller's investigation has sought evidence to support unproven claims that the Trump campaign colluded with Russians to impact the 2016 presidential election

The president routinely refers to Mueller's work as a 'witch hunt,' but he seldom goes after him by name.

Trump didn't explain what kinds of conflicts of interest he believes the special counsel hasn't made public.

Mueller released a standard financial disclosure in August 2017, and he is expected to file another this summer.

Trump's twitter outburst at Mueller and his '13 Angry Democrats' ignored Mueller's 30-page financial disclosure filed last year, and the fact that he's a registered Republican

The 30-page filing described nearly $3.5 million in income since 2016 from WilmerHale, a law firm where he represented Apple, Facebook, Intel, the NFL and Sony Pictures.

He earned $162,000 in speaking fees and listed a joint net worth with his wife of between $4.2 million and $15.2 million.

Mueller's past political donations are a matter of public record. He isn't required to declare the nature of personal relationships or his history of voting in federal elections.

James Comey, who Trump fired in May 2017, said this year in an ABC News interview that he and Mueller are not chummy allies, despite media accounts to the contrary.

'He and I are not close friends, but I've known him and watched his work,' Comey said in April.

Trump regularly complains that '13 Angry Democrats' are helping Mueller advance his probe into unproven charges that the Trump campaign colluded with Russian agents to influence the 2016 election.

Some members of his team have histories of donating to Democratic candidates. But Mueller is a registered Republican.