The first alarm came shortly after eleven o'clock on Monday night.
Then a person called the police after hearing bangs at Bagartorpsringen in Solna.
Police, however, found no trace of any shooting, but later that night another person called after finding traces of shooting against a gate in an apartment building.
Just before one o'clock at night, shots were fired at an apartment in Kista, but no person was hit.
Investigated as a felony
Just a few minutes later, it was shot again, this time towards the gate and the stairwell to an apartment building in Tureberg in Sollentuna.
No person was met here either.
In all cases, the incidents are investigated as a serious gun crime, in Kista and Sollentuna also as a serious illegal threat.