Russia investigation seeks 1st charges, indictment announcement may come as soon as Monday, sources say

— -- The special counsel team investigating Russia's alleged meddling in the 2016 election and possible links to the campaign of President Donald Trump has sought charges against at least one unidentified target, ABC News has learned.

Sources tell ABC News an indictment announcement and arrest could possibly come as early as Monday.

A spokesman for the special counsel's office declined to comment.

CNN first reported a federal grand jury approved charges brought by Special Counsel Robert Mueller’s team.

Attorneys from Mueller's office were at the federal courthouse in Washington, D.C., on Friday, including one of his senior prosecutors who specializes in fraud cases. ABC News confirmed a filing was made at the court Friday.

It's unclear at this point how significant this potential action might be.

Mueller is investigating whether there was any collusion between members of the Trump presidential campaign and Russia in connection with the 2016 election. The special counsel has also been probing the financial dealings of some key Trump associates.

Sources close to former Trump campaign chairman Paul Manafort told ABC News that they have no indication that any charges against him may be imminent.

ABC News also reached out to people associated with former National Security Adviser Michael Flynn and have so far not received a comment in response.