The charges, which are under seal, would be the first from the investigation into the attack in Benghazi nearly one year ago.
The CNN, citing people briefed on the matter, said yesterday that the charges were against Ahmed Khattalah, the leader of a Libyan militant group suspected of being behind the attack.
The Wall Street Journal, citing "people familiar with the matter," also reported charges had been filed, but did not specify against whom.
The Justice Department refused to comment to AFP, saying only that "the department's investigation is ongoing. It has been, and remains, a top priority."
Republicans have accused the Obama administration of deliberately trying to cover up what happened.