Updated at 1:26 p.m. ET

President Trump issued an eyebrow-raising tweet Friday morning.

"I am being investigated for firing the FBI Director by the man who told me to fire the FBI Director! Witch Hunt," he wrote.

Trump's tweet comes less than a day after a strange statement from a senior official in his administration.

On Thursday night, Deputy Attorney General Rod Rosenstein issued a statement in which he cautioned Americans against believing stories about the Department of Justice Russia investigation that cited unnamed sources:

"Americans should exercise caution before accepting as true any stories attributed to anonymous 'officials,' particularly when they do not identify the country — let alone the branch or agency of government — with which the alleged sources supposedly are affiliated. Americans should be skeptical about anonymous allegations. The Department of Justice has a long-established policy to neither confirm nor deny such allegations."

Though Rosenstein did not explain what prompted the statement, many political observers connected it to recent reports that special counsel Robert Mueller, who is leading the DOJ investigation into Russian election meddling, is also investigating whether Trump attempted to obstruct justice. Although USA Today also noted that the tweet came shortly after a Washington Post report that Mueller's team is also investigating Trump son-in-law and adviser Jared Kushner's business dealings.

After Trump's tweet Friday morning, a person close to the president's legal team told NPR's Scott Horsley that the tweet referred to the Wednesday Washington Post report regarding possible obstruction of justice. The tweet was not confirmation that the president or his attorney has been informed by the Department of Justice or Mueller that Trump is the subject of an investigation.

Mueller took over the DOJ Russia probe after a chain of events set in motion by Trump, Rosenstein and Attorney General Jeff Sessions.

In a May 9 memo, Rosenstein lambasted then-FBI Director James Comey for his handling of the investigation into Hillary Clinton's private email server. Trump initially used that memo along with a recommendation from Sessions to justify firing Comey. But soon after the abrupt termination, Trump told NBC News that he had been going to fire Comey regardless of any recommendations.

After the firestorm caused by Comey's firing, Rosenstein appointed Mueller, Comey's predecessor as FBI director, to take over the DOJ Russia investigation. (The decision to tap Mueller was left to Rosenstein because Sessions had recused himself from any involvement in the investigation owing to his role in Trump's presidential campaign.)

On Wednesday, The Washington Post reported that Trump was under investigation for obstruction of justice, citing unnamed officials. While the investigation had originally been focused on potential collusion between the Trump campaign and Russia, thePost reported, the obstruction inquiry began after Trump fired Comey.

Through a spokesman, Trump's personal attorney, Marc Kasowitz, blasted thePost's report, though he stopped short of denying it.

"The FBI leak of information regarding the president is outrageous, inexcusable and illegal," said Mark Corallo, the spokesman, according to thePost.

In light of Trump's concern about leaks, it's possible that Rosenstein's Thursday night statement was aiming to appease a president who has himself often criticized the news media for citing unnamed sources.

If that is the case, it could be part of what appears to be a pattern of statements that are intended to back the president.

After the "mother of all bombs" was deployed to fight ISIS in Afghanistan in April, a U.S. Central Command spokesman appeared to affirm Trump's aggressive statements against the Islamic State.

"We mean business," he said, as The Hill reported. "President Trump said prior that once he gets in he's going to kick the S-H-I-T out of the enemy. That was his promise and that's exactly what we're doing."

CENTCOM later said that person was "unauthorized" to speak for the command and that the statement was "inappropriate."

Likewise, CIA Director Mike Pompeo in February responded to a Wall Street Journal story that agents were withholding intelligence information from the president.

"The CIA does not, has not, and will never hide intelligence from the president, period. We are not aware of any instance when that has occurred," Pompeo said in a statement.

Trump's tweet Friday morning came after a series of angry tweets Wednesday in which he also complained about a "witch hunt" and criticized the investigation into ties between his campaign and Russia as "a phony collusion with the Russians story."

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