Drones continue to buzz over US bases. The military isn’t sure why and how to stop them.

A series of drone sightings over military bases across the country have renewed concerns that the US doesn’t have clear government-wide policy for how to deal with unauthorized incursions that could potentially pose a national security threat.

​ A series of drone sightings over military bases across the country have renewed concerns that the US doesn’t have clear government-wide policy for how to deal with unauthorized incursions that could potentially pose a national security threat. Read More Breaking News, Latest News and Videos | CNN