The shooting took place in the inner courtyard of an apartment building in the Fosie suburb.
One of the injured was rushed to hospital in an ambulance, with the other three making their own way, Malmö police said in a statement. Police are treating it as a murder attempt.
The shooting took place at around 6.50pm on Sunday, with the police alerted shortly after 7pm.
Witnesses reported hearing several loud bangs, after which two people were carried away to cars which then fled the scene. “Feet were sticking out of the car windows,” one witness said.
Another witness told the local Sydsvenskan newspaper that two mopeds were circling the area in the moments before the shots were fired. A third said they had seen a masked man on a moped open fire on one of the cars.
“On one moped, there were two masked people and on the other just one person. Both disappeared from the scene after the firing,” the witness said.
According to Swedish television, a crowd of more than 100 people arrived at the hospital to visit the wounded, forcing police to cordon off the emergency department, letting in only the closest relatives.
Sara Didrichsen from the Malmö police told Sydsvenskan that police were now seeking witness statements from local residents. “We are carrying out witness interviews and knocking on doors,” she said.
One local resident told Sydsvenskan that the shooting had made her feel the neighbourhood was no longer safe.
“I like it here, but now I'm really scared,” she said. “There are loads of kids who live here and are out playing.”