Police did not share any information about the suspects in the statement announcing the arrests, but have since confirmed a report in tabloid Aftonbladet that the victim was a witness to a previous shooting in the city last January, where a 16-year-old boy was killed.
They did not however want to speculate over whether that may have been a motive for Thursday's shooting.
“I can't speculate about that. We know that there is an incredibly complex situation between different individuals. That's part of the investigation, and the whole situation in Malmö and what we need to do to get at it,” police spokesperson Ewa-Gun Westford told news agency TT.
The man killed on Thursday died of his injuries after being shot at in the Rosengård district of the southern city, shortly before 7pm. When police arrived on the scene, the injured man had already been taken to hospital.
Eyewitnesses said he received multiple shots, and reported seeing a moped ride away from the scene.
A burning scooter was later found a few hundred metres away, according to regional paper Sydsvenskan, which also said the man was known to police and had previously been threatened.
A press officer at the local police department could not confirm whether the man was shot once or more, and did not want to comment on reports the victim had previously received threats to his life.
The shooting is the sixth in Malmö since the start of 2017, SVT reports. It came less than 24 hours after a 25-year-old man was seriously injured in the city's southern district of Linderbord.
Malmö, including its Rosengård district, regularly hits the headlines over gun crime, much of it believed to be gang-related. Last summer police stepped up their presence in the area following a spate of grenade attacks.
At the time, the city's police chief told The Local that much of the violence was down to “internal disputes between people who often had a criminal past”, and that the general public tended not to be the target.
READ MORE: Another side of Malmö's infamous Rosengård