Shots were fired around 8pm as a group of six people armed with weapons began fighting at the hospital.
“They are people from two families that are in a dispute. But I don’t want to say more,” police spokesperson Björ Blixter told the Expressen newspaper.
One man reportedly shot into a car and then disappeared from the scene in another vehicle.
No one was seriously injured in the melee, and police were able to recover a handgun and shell casings.
Police have also released a description of the suspected shooter in order to reduce the risk that someone might try to protect the man.
“We usually don’t release a description, as that can affect witnesses’ recollections of events. But in this case the public interest and our need to clear up the case are more important,” Blixter told the TT news agency.
The suspected shooter has been described a bald male in his thirties between 1.6 and 1.65 metres tall. He was reportedly wearing dark clothes at the time of the shooting.
The gun fire sparked a massive police operation in Gothenburg late Wednesday night and twelve people were detained for questioning.
As of Thursday morning, four people were still being held, two of whom remained at the hospital for treatment for injuries caused by something other than gunfire.
Two were being held in connection to the brawl and shooting, and two for suspected weapons crimes uncovered in the course of police’s response to the incident.
Four cars have also been impounded, one in connection with the suspected weapons crime. In addition, one of the three other cars had damage caused by gunfire.
Police remain uncertain as to what exactly caused Wednesday night’s fight and subsequent shooting, but indicated there may be a connection to a brawl which erupted at Sahlgrenska’s intensive care ward late Tuesday night involving around 30 people from two different families.
Following the Wednesday night shooting, police have launched a preliminary investigation into attempted murder.
“We’re working hard and trying to get a clear picture of what happened,” police spokesperson Stefan Gustafsson told Expressen.