Captain Robert Salas was on duty in Montana in 1967 when a UFO shut down the nuclear missiles on his base. And he's hardly the only one to make such a claim.

On Monday, six former U.S. Air Force officers and one former enlisted man will break their silence about similar events at the National Press Club, all centering around unidentified flying objects and nuclear missiles. They plan to urge the government to publicly confirm the incidents, stating that they were ordered never to discuss the events.

"We're talking about unidentified flying objects, as simple as that," Salas told FoxNews.com. "They're often known as UFOs, you could call them that," he added. Salas, a former U.S. Air Force nuclear missile launch officer, will host the event along with researcher Robert Hastings, author of "UFOs and Nukes: Extraordinary Encounters at Nuclear Weapons Sites.

According to the pair, witness testimony from more than 120 former or retired military personnel points to an ongoing and alarming intervention by unidentified aerial objects at nuclear weapons sites, as recently as 2003. In some cases, several nuclear missiles simultaneously and inexplicably malfunctioned while a disc-shaped object silently hovered nearby.

"I was on duty when an object came over and hovered directly over the site," Salas said, regarding the March 16, 1967, event at Malmstrom AFB in Montana. "The missiles shut down, 10 Minuteman missiles. And the same thing happened at another site a week later," he said.

Are they evidence of unknown military action from a foreign country, or are these extraterrestrial visitors? Salas thinks the answer is clear -- and finds it curious that they're so interested in our nuclear arsenal.

"There's a strong interest [in our missiles] by these objects, wherever they come from. I personally think they're not from planet Earth."

Another participant, retired Col. Charles Halt, observed a disc-shaped object directing beams of light down into the RAF Bentwaters airbase in England and heard on the radio that they landed in the nuclear weapons storage area. Both men claim the Air Force warned them never to disclose details of the events.

"The U.S. Air Force is lying about the national security implications of unidentified aerial objects at nuclear bases and we can prove it," Salas said. Col. Halt adds, "I believe that the security services of both the United States and the United Kingdom have attempted -- both then and now -- to subvert the significance of what occurred at RAF Bentwaters by the use of well-practiced methods of disinformation."

The group plans to distribute declassified U.S. government documents at the event that they claim will substantiate the reality of UFO activity at nuclear weapons sites extending back to 1948. The press conference will also address present-day concerns about the abuse of government secrecy as well as the ongoing threat of nuclear weapons.

"This is only the tip of the iceberg, these stories," Salas told FoxNews.com.