The U.S. government's official line may be that unidentified flying objects (UFOs) don't pose a national security threat, but a group of former Air Force officers gathered Monday in the nation's capital to tell a different story.
During a press conference at the National Press Club in Washington, D.C., seven former Air Force officers once stationed at nuclear bases around the country said that not only have UFOs visited Air Force bases, some have succeeded in disabling nuclear missiles stationed there.
"I want the government to acknowledge that this phenomenon exists," said Robert Salas, a former U.S. Air Force Nuclear Launch Officer. "I want the Air Force, the government to come forward and say this is a real phenomenon."
But Salas said it's a "falsehood" that UFOs are not a national security threat and claims he speaks from firsthand experience.
He was stationed 60 feet underground at the Malmstrom Air Force Base in Montana in March 1967, monitoring the launch control center for 10 nuclear missiles when he received a call from a guard above ground.
"He calls down saying they've been seeing some strange lights in the sky making odd maneuvers, very silent, he knows they're not airplanes," he said.
At first Salas didn't pay much attention to the report, he said. But then he received a second phone call.
"He calls back about five minutes later and this time he's screaming into the phone. He's very frightened, I can tell by his voice," Salas said. "And he said, 'Sir, I've got all the guards out here, they've got their weapons drawn, we're all looking at an orange or reddish pulsating oval-shaped object. It's about 30 feet in diameter and just hovering above the front gate. "
Thinking they were under some kind of attack, Salas said he told the guards to keep it outside the perimeter of the gate.
As he alerted the other officer stationed with him underground, he said he noticed that the missiles started going offline.
"The missiles started going into 'no go' or unlaunchable condition. They were essentially disabled while this object was overhead," he said.
The unidentified object eventually took off ? and the missiles didn't suffer permanent damage ? but he said it took about a day to get the missiles back up and running.
"Nobody was injured and I don't consider it an attack but it certainly it was a national security incident and something the Air Force said has never happen in their official policy documents," he said.
When contacted by ABC News, an Air Force spokeswoman declined to comment and pointed to the Air Force's official position on UFOs outlined on its website.
According to that statement, after investigating UFOs from 1947 to 1969, the Air Force concluded that there was no evidence indicating that sightings considered "unidentified" were extraterrestrial in origin.
"No UFO reported, investigated and evaluated by the Air Force was ever an indication of threat to our national security," the statement said. "There was no evidence submitted to or discovered by the Air Force that sightings categorized as "unidentified" represented technological developments or principles beyond the range of modern scientific knowledge."
Salas said he doesn't think the UFOs he claims to have encountered had any offensive intent, but he believes they wanted to leave an impression.
"I think it was simply a show. They wanted to shine a light on our nuclear weapons and just send us a message," he said. "My interpretation is the message is get rid of them because it's going to mean our destruction."
Other former officers recounted similar stories of unexplained moving lights and odd-shaped flying objects during their time in the service, media reports said. Some said it was difficult to talk about their experiences with friends and family.
Leslie Kean, an investigative journalist and author of the new book "UFOs: Generals, Pilots, and Government Officials Go on the Record," said thousands of pages of documentation support the officers' accounts. She spent the last 10 years researching UFOs and combing through thousands of pages of declassified government material.
Some documents even show that Air Force officials themselves believed the UFO reports were concerning, she said.
Kean said that one declassified document that she researched for her book, relating to the Salas incident, said, "the fact that no apparent reason for the loss of the 10 missiles can easily be identified is a cause for grave concern to this headquarters."
Since the 1970s, the Air Force has said investigations and evaluations of UFO reports have never given any indication that UFOs are a threat to national security, she said.
"These cases show that that just isn't true," she said. "The men involved with these cases have made statements that they don't believe this to be true."
Popular culture may equate UFOs with sci-fi movies and fantastical extraterrestrial beings, but she said most people misunderstand what UFOs actually are.
"What we actually know about UFOs is there is clearly a physical phenomenon that is well documented by officials, by government agencies, around the world," she said, adding that it shows up on radar and film, leaves marks on the ground and can affect aircraft instruments.
She said that given what eyewitness accounts and documentation indicate, it's time for the government to give it the attention it deserves.
"Since there is this physical phenomenon that's there, the question is, what do we do about it?" she asked.