Police first received reports of a shooting at 1.20am, and when they arrived at the scene they found two men with severe injuries. Both victims, aged 40 and 45, died later in the night, and their relatives have been informed.

Several areas of the town centre were cordoned off early on Thursday morning for technical investigation.

“We have around ten patrols at the scene at the moment,” said police press spokesperson Thomas Agnevik shortly after 3am. “There are several witnesses who saw things and we have spoken with some of them.”

• The stats that explain how Sweden has been affected by gun crime

No other people were injured in the shooting, but several windows at a nearby restaurant were damaged. 

And a man in his 20s was injured in a shooting in Katrineholm, about 50 kilometres north of Norrköping, on the same night. He was described as seriously injured but in a stable condition.

Swedish police recently announced a 'special national incident' to look into violent crime in Sweden, with the aim of reducing the number of explosions and shootings. This means that a temporary task force is set up to focus solely on the specified problem, and is given extra powers to make decisions and allocate resources to facilitate investigation and crime prevention.

Sweden's crime and homicide rates are both low when compared with many other countries, and previous decades in Sweden. But while the overall murder rate has not changed much in Sweden, the proportion of murders where a gun was used, and the proportion that are linked to gang violence, have risen over the past decade.  

• What is a 'special national incident' and why has Sweden just announced one?