Ali, 10, died from his injuries in hospital on Saturday. The boys' father received mourners at his temporary home after news broke of the death, the Guardian reported.
Ali was not with his younger brother at home but playing with friends out in the street when the bomb fell on Wednesday. While his family sustained minor injuries when their home collapsed he was more seriously hurt in the blast.
Kenan Rahmani, a Syrian activist wrote online: "Omran became the 'global symbol of Aleppo's suffering' but to most people he is just that -- a symbol. Ali is the reality: that no story in Syria has a happy ending."
There is growing frustration in rebel-held Aleppo that grief at the plight of Omran has not been accompanied by rage at those who dropped the bomb.
The image brought renewed global focus to the suffering of civilians in the eastern part of Syria's largest city, living under near-siege conditions.
"All Syrians, and me, thank the world for their feelings of sorrow, but why don't you help us to find peace," asked Aisha, a mother of two who fled the city after barrel bombings intensified but who still lives in the countryside near Aleppo. "The cause of this is Bashar al-Assad," the Guardian quoted her as saying.
