Saturday morning saw a fake invasion of southern Stockholm, reports Swedish Television SVT.
The areas of Gröndal, Hägersten and Aspudden south of the city centre were the scene of the military exercise.
"It will be going on all day, between 8am and 6 pm, with shooting and the like," says Dan Grip at the police communications room.
Since Gröndal is on a peninsula on the western shore of Stockholm the noise travelled over the lake water and reached north western Stockholm-
But the gunfire that woke Stockholmers on the Essingen islands and around Bromma was only blanks being let off.
"We have had a lot of people ringing in" says Dan Grip," with a sigh, reports SVT.