President Trump confirmed Friday that he is under investigation for firing FBI Director James Comey.

In a series of tweets, Trump lashed out against the investigation into whether his campaign colluded with Russia to influence the 2016 election. The probe has reportedly expanded to include whether Trump fired Comey in an attempt to obstruct justice.

He also claimed that the person investigating him advised him to fire Comey, though it’s unclear whom he was referring to. Attorney General Jeff Sessions recused himself from the investigation, and Deputy Attorney General Rod Rosenstein appointed Robert Mueller to oversee it in the wake of Comey’s ouster.

I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt — Donald J. Trump (@realDonaldTrump) June 16, 2017





When Trump fired Comey, Rosenstein drafted a memo accusing the FBI director of bungling the investigation into Hillary Clinton’s email server, and Sessions wrote a letter saying the dismissal was warranted. Mueller has not made any public comments about Comey amid the firestorm.

Until Trump’s Friday-morning Twitter burst, only the Washington Post’s sources had indicated that Trump was being investigated for possible obstruction of justice. Trump had previously boasted that he was not personally under investigation, and Comey said the president had repeatedly pressured him to publicly clear him.

The missive was the latest in an ever-escalating Twitter tirade targeting the Russia inquiry.

After 7 months of investigations & committee hearings about my "collusion with the Russians," nobody has been able to show any proof. Sad! — Donald J. Trump (@realDonaldTrump) June 16, 2017





You are witnessing the single greatest WITCH HUNT in American political history – led by some very bad and conflicted people! #MAGA — Donald J. Trump (@realDonaldTrump) June 15, 2017





Story continues

They made up a phony collusion with the Russians story, found zero proof, so now they go for obstruction of justice on the phony story. Nice — Donald J. Trump (@realDonaldTrump) June 15, 2017





Thursday, Trump griped he was receiving unfair treatment from investigators compared with his election opponent, Hillary Clinton.

Why is that Hillary Clintons family and Dems dealings with Russia are not looked at, but my non-dealings are? — Donald J. Trump (@realDonaldTrump) June 15, 2017





Crooked H destroyed phones w/ hammer, 'bleached' emails, & had husband meet w/AG days before she was cleared- & they talk about obstruction? — Donald J. Trump (@realDonaldTrump) June 15, 2017





President Trump (Photo: Olivier Douliery/Getty Images)

Read more from Yahoo News:

More on the shooting at GOP baseball practice: