It was just after four on Friday morning that several Växjö residents heard a loud bang. The explosive charge thundered outside an apartment.
"It was outside an apartment on the second floor of a two-story house," said Robert Loeffel, a police spokesman.
The blast caused material damage to the property and several windows were crushed.
- There was no banger or other pyrotechnics. Those who have done this knew what they were doing, says Robert Loeffel.
No one was in the apartment when it slammed. The police have later arrested several people who live in the apartment in question.
During the day, the national bomb protection was in place and carried out an investigation of the area.
Police are now searching for witnesses and testimonies and have set up a mobile police station nearby in the hope of finding people who have seen something.