A public affairs division of the U.S. Department of Defense has come under fire for a tweet that appeared to threaten to kill civilians who had been drawn to a secretive military base in Nevada rumored to house government secrets about extraterrestrial life and spaceships.

Prompted by a Facebook post inviting people to "Storm Area 51," UFO enthusiasts poured into rural Nevada on Friday near the base, known colloquially as Area 51, but fears of a mass raid on the remote site or a public safety crisis proved unfounded, with just three people arrested.

Instead, perhaps the most excitement came in the form of a tweet by the official account of the Defense Media Activity (DMA)'s Defense Visual Information Distribution Service (DVIDS) late Friday that showed a B-2 stealth bomber on a runway surrounded by servicemembers.