"We have confirmed the identities of the dead, and their families have been informed," Stockholm police official Jan Evensson told reporters on Sunday.
Police would not reveal the identities of the victims, but three have later been named as Briton Chris Bevington, Belgian Maïlys Dereymaeker and 69-year-old Swede Lena Wahlberg from western Sweden. The fourth victim was an 11-year-old girl.
Bevington was a 41-year-old who worked for Spotify and lived in Stockholm.
His father, John Bevington, said in a statement: "We are all devastated by the untimely and tragic death of our talented, compassionate and caring son Chris."
"A wonderful husband, son, father, brother and close friend to many. The family requests absolute privacy at this incredibly difficult time to mourn his passing in peace."
A photo of Chris Bevington, released by his family. Photo: AFP PHOTO/Family handout via Foreign & Commonweatlh Office
The suspected perpetrator of the attack was scheduled to be deported from Sweden, but authorities had not been able to enforce the expulsion, police also said at a press conference on Sunday.
The man, a 39-year-old Uzbek national named Rakhmat Akilov, had unsuccessfully applied for residency in Sweden and is also reported to have shown ‘interest' in terror group Isis. He has admitted to the attack.
Eight people are still being treated for injuries sustained during Friday's attack, according to Stockholm Municipality's press office on Tuesday. Two remain in intensive care.