One of the men has been able to leave hospital. The other two are described as having serious and life-threatening injuries, respectively. The fourth died in hospital on Monday.
Police are investigating the shooting, which broke out on Sunday evening in a street in the southern city's Fosie district. Witnesses speaking to Swedish media said that there had been a car chase, with the four victims in one vehicle and the shooters pursuing them on scooters and later fleeing the scene.
But police are struggling to convince more witnesses to come forward.
“It is difficult today to get details and that's because people are a little afraid to talk to us and to get mixed up in something they have nothing to do with,” police spokesperson Claes-Arne Hermansson told the TT news agency.
He describes the victims as young men in their twenties, some of whom are previously known to police.
Police were on Tuesday still looking for two to three shooters, who picked up their weapons and shot off what witnesses described as some 20 rounds after the car being chased rammed into a tree on Censorsgatan in Malmö.
A police investigator told Swedish radio on Monday that at least one bullet, but possibly two, had gone straight into a nearby apartment, missing a child by “centimetres”.
“We think it is very serious that you don't think about the fact that there actually are more people than the ones you are angry at who could get really hurt,” Hermansson told TT.
“I am not surprised, but think it is terribly nasty that it should happen,” he added.
As The Local has previously reported, while Sweden is generally a peaceful, safe country with low crime rates, police have had difficulty addressing violence in poorer neighbourhoods in Stockholm, Gothenburg and Malmö.
In recent years, there have been grenade attacks, shootings and incidents of car arson.
At the end of August, an eight-year-old child was killed when a grenade was thrown into the apartment where he was sleeping.
One of the people registered at the address was a person who had been convicted for murder in a settling of scores between members of the Somali community in Gothenburg, police said at the time.