Several of the people injured are said to be part of motorcycle gang Hells Angels, reports Swedish news agency TT, although the prosecutor declined to confirm which groups were involved.
“The incident appears to have been sparked by a conflict, which either arose during the course of the evening or existed previously, between two different groups – one with links to motorcycle gangs and the other with local connections,” Sweden's prosecution authority said in a statement.
Seven people were taken to hospital in Gothenburg after the shootout on Saturday evening.
Some had gunshot wounds while others had been stabbed or assaulted. By Sunday evening one had been able to leave hospital, five were in stable condition and a seventh remained seriously injured. An eighth person believed to be linked to the incident sought care at a hospital in Skaraborg, writes TT.
The prosecutor has until Wednesday to decide whether to ask court to have the 11 men remanded in custody. They are aged between 25 and 50 and suspected on reasonable grounds of attempted murder and aggravated assault. Thirteen people were initially held. Of those, one had not yet been questioned by Sunday evening and another has been released.
Motorcycle gangs Hells Angels and Bandidos were involved in several violent conflicts in the 1990s, but since then such incidents have been less common in Sweden.
A forensic examination of the scene of the shooting, which took place at a party venue according to local media, was still ongoing on Sunday evening. The area, around 500 metres from the bus and railway station in Mölnlycke and home to a number of small businesses, was cordoned off.
Mölnlycke is located a couple of kilometres south-east of Gothenburg in western Sweden.