UFO's or Spy Balloons, what are we shooting out of the sky?

White House officials said Monday that three unidentified flying objects shot down since Friday posed a “very real” threat to civilian air traffic but were not sending out communications signals.

John F. Kirby, a spokesman for the National Security Council, also said the military had not yet identified the source of the objects or what their purpose was. And he said there was no indication that Americans on the ground were in danger.