US Air Force warns against joke event to ‘storm Area 51’

The Alien Research Center, a retail souvenir shop located near the military testing base known as Area 51 in Rachel, Nev., Aug. 20, 2013. (Isaac Brekken/The New York Times)

The US Air Force has warned people against participating in an internet joke suggesting a large crowd of people "storm Area 51," the top-secret Cold War test site in the Nevada desert.

A prank event on Facebook that’s attracted more than 1 million interested people suggests that a mass of people attempt to run into the mysterious site at 3 a.m. on September 20.

The site is part of the vast Nevada Test and Training Range and has become the center of UFO conspiracy theories.

The Facebook event jokes "they can’t stop all of us" and "Let’s see them aliens."

Nellis Air Force Base said in a statement that the Air Force is aware of the Facebook posting and says "any attempt to illegally access the area is highly discouraged."

Read | Storm Area 51? It s a joke, but the Air Force is concerned

The Air Force says it does not discuss its security measures and that the test and training range provides "flexible, realistic and multidimensional battlespace" for testing and "advanced training in support of US national interests."

After decades of government officials refusing to acknowledge Area 51, the CIA released declassified documents in 2013 referring to the 8,000-square mile (20,700-sq. kilometer) installation by name and locating it on a map near the dry Groom Lake bed.

The base has been a testing ground for a host of top-secret aircraft, including the U-2 in the 1950s and later the B-2 stealth bomber.

But secrecy surrounding the site has fueled conspiracy theories among UFO enthusiasts and sprouted a small, alien-themed tourist industry in surrounding desert communities, including alien-themed cafes, an alien-themed motel and an alien-themed brothel.