The U.S. Navy is drafting new guidelines for pilots and other employees to report encounters with "unidentified aircraft." The effort comes in response to more sightings of unknown, advanced aircraft flying into or near Navy strike groups or other sensitive military facilities and formations, according to the service. "There have been a number of reports of unauthorized and/or unidentified aircraft entering various military-controlled ranges and designated airspace in recent years," the Navy said in a statement to Politico, which first reported the move. "For safety and security concerns, the Navy and the [U.S. Air Force] takes these reports very seriously and investigates each and every report." Read more about the new guideline effort on Military.com.