US president Donald Trump has told his Twitter followers that they are witnessing the "single greatest witch hunt in American history".
Mr Trump did not clarify what exactly he was referring to in the early morning tweet, although he has frequently described reports about possible ties between members of his campaign and Russia as a "witch hunt".
He wrote: "You are witnessing the single greatest WITCH HUNT in American political history - led by some very bad and conflicted people! #MAGA" - the acronym referring to his campaign slogan, Make America Great Again.
Earlier on Thursday, Mr Trump tweeted that a new report suggesting that special counsel Robert Mueller may investigate him for possible obstruction of justice after he sacked FBI director James Comey is a "phony story".
He said on the micro-blogging site: "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."
The Washington Post reported that special counsel Robert Mueller is seeking interviews with three Trump administration officials who were not involved in his campaign.
Those officials are: Dan Coats, the director of national intelligence; Michael Rogers, the head of the National Security Agency; and Richard Ledgett, the former NSA deputy director.
Accusations of obstruction arose last month when Mr Trump sacked FBI director James Comey. Mr Comey told US Congress last week that he believed he was fired "because of the Russia investigation".
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