'Witch hunt': Trump at odds with White House over Robert Mueller

US President Donald Trump on Thursday lashed out the appointment of a special counsel to probe allegations of his campaign's collusion with Russia into last year's general elections, calling it the single greatest "witch hunt" of a politician in American history. The Justice Department named former FBI Director Robert Mueller as special counsel to investigate alleged Russian interference in the 2016 US election and possible collusion between Trump's campaign and Moscow.

The decision by deputy attorney general Rod Rosenstein to appoint Mueller, 72, as special counsel came following a week of turmoil for the White House after Trump fired FBI Director James Comey, who had been leading a federal probe into the matter. Reacting to the appointment, Trump earlier said a thorough investigation will prove that no such collusion took place.