Candles were attached to the balloons during the superstitious game
More than a dozen UFO sightings were reported to police after partygoers attached candles to balloons and released them into the night sky.
Saturday night revellers in Grangemouth, Stirlingshire, were said to be playing a mystery game.
But residents in the surrounding area believed the illuminated objects were an alien invasion.
A spokesman for Central Scotland Police said: "We've had call, after call, after call, saying it's UFOs."
He said they received more than a dozen calls in half an hour.
"It turns out that there's a party going on and they are letting off balloons with candles on. They make a wish and then release them into the sky."