The explosion took place at 01:30 local time (23:30 GMT on Sunday), no one got injured in the accident, Sydsvenskan newspaper said, citing police.
“It caused serious damage to the building. As far as I know, no one was injured,” police officer Martin Karlsson was cited by the news outlet as saying.
Reportedly, the explosive device was placed in front of the entrance after the night club was closed. The sound of explosion was so loud that it awoke residents of the neighborhoods close to the site of accident, the newspaper said.
Searches for suspects are ongoing, the news outlet added.