Several dozen people - rather than the two million feared - showed up on Friday near a secretive US military base in the Nevada desert, answering a meme-inspired Facebook event to storm the site in search of aliens.

The revelers, some wearing alien masks or tin foil hats, began gathering at the suggested time of 3:00 am Friday near the base known as "Area 51," but they did not attempt to storm the heavily-guarded site.

The "Storm Area 51" invitation has meanwhile spawned weekend festivals in the two tiny Nevada towns of Rachel and Hiko, which are located near the site, about a two-and-a-half-hour drive from Las Vegas.