Police were called out to the scene on the Drottninggatan street in central Landskrona shortly after 10pm on Wednesday, after several people reported hearing a loud bang.
They said in an update on their website that “something had exploded at the city hall”, causing among other things windows to shatter. No one was injured in the incident.
Torkild Strandberg, the Liberal mayor of Landskrona, hit out at the as of yet unknown perpetrators, but told the TT news agency that the fact it happened outside the council building was of no special significance.
“No matter which building it is, you're putting people in danger, you're overstepping all written and unwritten rules,” he said, adding that council work would carry on as normal on Thursday.
Landskrona, a town of just above 32,000 residents, has been fighting a spate of gang crime this summer, with three murder attempts and explosives placed in central parts of the city.
“There's a strong sense of frustration and a desire not to accept this. There's more anger and irritation than anything else,” Strandberg told TT.
Police lifted the cordons around the scene shortly after 4am. No arrests had been made at that time.