According to police, the four suspects are aged 34, 30, 27, and 21.
Two of the four men had previously been held in custody on suspicions of their role in the killing, Bo Lundqvist of the Malmö police told the TT news agency.
He explained that police had new information that once again made the two men prime suspects in the case.
One of the four men has previously been notified he was under suspicion of protecting a criminal.
“All four are now suspected of murder,” said Lundqvist.
“All deny committing the crime.”
According to Lundqvist, the four men were arrested on Thursday.
Search warrants were carried out at two addresses and on several vehicles in connection with the arrests and several weapons were confiscated.
Following the arrests, the men have also come under suspicion of weapon and drug offences.
The murder took place in broad daylight on a Sunday afternoon in August when several masked men fired several shots at the 19-year-old near a kebab stand on Lönngatan in central Malmö.
“I saw how a man went up to the guy with a gun. He fired two or three shots at the man’s head at close range and then ran across the street,” a witness told the Sydsvenskan newspaper.
When police arrived on the scene, they found the 19-year-old laying among the tables and chairs next to the food stand.
Witnesses reported seeing several men flee from the scene by foot and by car.
Police arrested three suspects following the killing, which they characterized as an “execution” related to the settling of scores among criminal gangs.
Two suspects were previously remanded in custody for the killing, and while they were released in early December, prosecutors indicated they were still suspected for the murder.
It remains unclear if the warrants issued on Friday are for the same suspects that had been arrested shortly after the killing.
According to Sydsvenskan, the 19-year-old victim had ties to several criminal gangs.
At the time of the killing, he was sitting next to a man known as the “Sweden leader” for the Outlaws, a former member of the Original Gangsters, and another man.
The 19-year-old had himself been active in the Black Cobra gang, according to Sydsvenskan, but had been kicked out because other gang members didn’t consider him able to meet the demands of membership.
During Friday’s press conference, Skåne police commissioner Mikael Mattsson explained that investigators still don’t see anything pointing to a connection between the eight murders currently under investigation.
However, he emphasized that both he and the chief of police in Malmö Ulf Sempert believe the attitude among Malmö residents has shifted recently and that many more people are willing to come forward with tips and cooperate with police.
“We’re talking about all types of people,” said Mattson.
“There’s an increase in the belief that the police can succeed in their work,” added Sempert.