The first charges have been filed in Robert Mueller's Russian Federation investigation, less than six months after the special counsel was appointed in the wake of James Comey's dismissal as F.B.I. director in May.
Plans were prepared Friday for anyone charged to be taken into custody as soon as Monday, sources told CNN.
Comey said during congressional testimony in June that he felt the president tried to pressure him into dropping the FBI's investigation into former National Security Advisor Michael Flynn four months earlier.
A CNN reporter admitted on the network Friday night that in typical cases, the person being indicted and their counsel are quickly informed of the indictment. Deputy Attorney General Ron Rosenstein signed the order.More news: Sailors survive 99 days lost at sea
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The Kremlin has also denied the claims. The nature of the charges is not clear, nor is the identity or number of individuals targeted.
Trump, a Republican who was elected president last November, has denied allegations that his campaign colluded with Russians and condemned investigations into the matter as a witch hunt. It also came after weeks of questions about the Justice Department's independence from the White House.
On Friday, top lawyers who are helping to lead the Mueller probe, including veteran prosecutor Andrew Weissmann, were seen entering the court room at the DC federal court where the grand jury meets to hear testimony in the Russian Federation investigation.
As Special Counsel he has sweeping powers and the authority to prosecute any crimes he uncovers.