The airstrike that destroyed the home of five-year-old Omran Daqneesh who was photographed after being pulled from the rubble has claimed the life of his brother.

Ali, 10, 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.

It emerged today that he had died from his injuries in hospital. The boys’ father received mourners at his temporary home after news broke of the death.

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 and a constant bombardment of barrel bombs dropped from government aircraft and more targeted Russian airstrikes.

But those who live every day with the fear that their homes will be the next target, that their children will be the next ones carried into an ambulance, say tears are not enough, and the world must push harder to end the war.

“All Syrians, and me, thank the world for their feelings of sorrow, but why don’t you help us to find peace?” said 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.”

They want an end to an aerial bombing campaign that has taken a disproportionate toll on civilians and point out that only one party to the conflict has aircraft. The rebels launch rockets into government-held areas, but their reach is far more limited than aircraft.

Russian and Syrian air force planes have a track record of hitting civilian targets, from schools to hospitals and markets, although both governments deny running a campaign of terror. Syrians have long been frustrated that western horror at atrocities by Isis has diverted attention from a far higher, but less publicised, civilian death toll at the hands of government forces and their allies.

Omran Daqneesh sits in the back of an ambulance following the airstrike. Photograph: Anadolu Agency/Getty Images

Civilian casualties from Russian bombings have overtaken civilian deaths at the hands of Isis for the first time, the activist group, the Syrian Network for Human Rights, said last week.

By ignoring the political and military context of Omran’s plight, they are cheapening his suffering and that of all the people who have chosen to stay on in opposition-held areas of Aleppo, or have not had an opportunity to leave.

“We don’t want the world to know we are dying as civilians here, that is not enough. We want the world to know who is killing us, who is targeting us,” said an English-language professor at the university, whose six-month-old daughter was born in one of the city’s few remaining hospitals. “If people in Britain and United States know that Russia and Assad are doing this, they will help us, they will do something with their government to help us. But if they don’t know, what kind of help can we get?”

There was anger about a video that went viral of CNN anchor Kate Bolduan struggling to hold back tears as she presented a segment on Omran, because she said it was not clear who had bombed his family’s apartment. “Their home is inside Aleppo, Syria. It was hit by a bomb, an airstrike. Who’s behind it, we do not know,” she said. That emotion was hailed by viewers outside Syria as an understandable human response to terrible tragedy.

For some closer to the violence, crying at Omran’s injuries without naming those responsible seemed more of a betrayal than a tribute. “While tears were pouring down her face, she talked about the child and his lost family, without mentioning who was behind it,” wrote one angry Facebook commentator, Abu Khled, frustrated that the coverage focused more on those bombed than the bombers.

“CNN is trying to deceive [viewers],” said Mohammad, a teacher in Aleppo who was trying to organise exams this month as the bombing continued. “We are all going to die if Assad remains president of Syria.”