"A spokesman with the Federal Aviation Administration (FAA) confirmed Wednesday afternoon that the craft were part of a military exercise, but couldn't identify the aircraft or their place of origin."
"Staff Sgt. William O’Brien, spokesman for Charleston Air Force Base, said the craft didn’t come from there. He said the base doesn’t perform military exercises in or around Horry County.
“We do not fly aircraft in your area, so it couldn’t have been one of ours,” O’Brien said. “It would not be anything that we fly because that’s not where we fly.”"
There's a lot more over at the source.