Following the blasts at housing complexes on the Swedish capital's northwestern outskirts, some 50 people were evacuated. The explosions, which damaged balconies, windows, doors and the interiors of several apartments, took place some 500 meters (yards) apart.
Sweden in recent years has seen explosions and shootings linked to feuding criminal gangs. Police did not explicitly link Tuesday's blasts to gangs but did not explain why terrorism was ruled out.
Tuesday's blasts occurred eight days after a predawn explosion rocked central Stockholm, damaging buildings and parked cars but causing no injuries. That explosion occurred outside the entrance to a building housing a business and several apartments and led to the evacuation of dozens of apartments.
Police have not made any arrests and are looking for video surveillance which could be used in the investigation. It was not clear what kind of explosives were used in Tuesday's blasts.