(CNN) A boy sits on a sidewalk barefoot, his head wrapped in a bandage. For the past three weeks, he hasn't heard the pummeling of air raids in the city.

Bombings had been temporarily stopped in Aleppo.

A wounded boy in Aleppo in the aftermath of Syrian airstrikes.

But Wednesday, his childhood of war resumed. His dad sits beside him holding one of his injured siblings. Behind him, his sister is covered in a red blanket. She's dead.

And life goes on for the boy in Aleppo.

The photo was shot after the Syrian government bombed rebel-held areas in the city.

At least 87 people, including four children, were killed in a Syrian regime blitz on war-ravaged eastern Aleppo and the surrounding countryside. The bombings pounded hospitals, a blood bank and targets near schools, activists and medical staff said.

The Al-Shaar neighborhood appeared to be the worst hit, with barrel bombs striking the Children's Hospital, Al-Bayan Hospital and the Central Blood Bank, staff on site with the Syrian American Medical Association (SAMS) told CNN. Buildings nearby were completely flattened.

and said three additional bodies had been recovered from bombings the previous day, when regime forces Bebars Meshaal from the Syrian Civil Defense, also known as the White Helmets, initially put the death toll at 27and said three additional bodies had been recovered from bombings the previous day, when regime forces resumed its air raid over eastern Aleppo after a three-week lull.

The death toll rose later in the day, with the White Helmets saying 22 people of those killed were in the village of Batbo. Fifty were injured there, the group said.

Children flee after airstrikes hit their neighborhood in eastern Aleppo on Tuesday.

Video of the aftermath in Aleppo shows White Helmets volunteers rushing to rescue a girl from the rubble of a toppled building.

The victim is carried away and doused in liquid from a water bottle to clear her sight.

She rubs her eyes for several seconds, but is unable to open them. Blood drips from her nose.

CNN has not been able to independently verify the impact of the strikes, having little access to the area.

The Aleppo Media Center (AMC) activist group said four killed children were in the al-Sukkari neighborhood, adding that more could be among the dead.

Children's Hospital Director Dr. Hatem, said he felt some 20 barrel bombs hit the facility and that staff members had hunkered down in the basement as the bombardment continued through the morning.

The hospital is run by the Independent Doctor's Association.

''A horrible day for the Children's Hospital. Me and my staff and all the patients are sitting in one room in the basement right now, trying to protect our patients," Hatem said earlier in a statement.

"Pray for us please," said Hatem, one of the last three pediatricians working at the hospital.

Medical staff on the ground said the Central Blood Bank had in October distributed about 1,500 bags of blood to 10 facilities in eastern Aleppo. The blood is a much-needed resource in an area pummeled by regular shelling.

126 attacks on health facilities

The World Health Organization (WHO) condemned recent attacks on three other hospitals in a rural area west of Aleppo city and two in Idlib province in which at least two people were reportedly killed and 19 people wounded.

A child in the aftermath of regime airstrikes in the Salaheddin neighborhood of Aleppo.

"Shockingly, such attacks on health in Syria are increasing in both frequency and scale," it said in a statement, adding that it had documented 126 such attacks across the country so far in 2016.

"The pattern of attacks indicates that health care is being deliberately targeted in the Syrian conflict -- this is a major violation of international law and a tragic disregard of our common humanity."

Pictures and videos posted by the AMC on social media show children, still wearing their school backpacks, fleeing through rubble from obliterated buildings in Karam al-Beik, near al-Shaar. One image shows a young girl in tears, holding hands with another.

Other children were wounded in a strike near a school in the Salaheddin neighborhood, the AMC said, adding that a medic was also killed.

Eastern Aleppo has become the wretched center of Syria's five-year conflict and the regime's siege has triggered a humanitarian catastrophe there, as food, water and medical supplies run low.

Blitz after text message warning

a The strikes that resumed Tuesday followed dire text message was sent en masse to residents in the east, essentially telling them to flee or be killed in the bombings.

There had been a three-week lull in eastern Aleppo air raids before the Syrian government blitzed the area Tuesday, using what the regime called "precision weapons to target terrorist positions."

JUST WATCHED Text messages warn people in Aleppo to 'leave or die' Replay More Videos ... MUST WATCH Text messages warn people in Aleppo to 'leave or die' 01:55

Rebels took control of eastern Aleppo in 2014, and government forces continue their siege of the area, battering it from above with the help of Russian air power.

Moscow has sought to distance itself from the blitz, with Deputy Foreign Minister Sergey Ryabkov saying Wednesday that the Russian air force had not carried out the Aleppo strikes, according to state-run news agency Tass.

A boy receives medical treatment after being injured in an airstrike Tuesday.

Trump: Assad's friend or foe?

Following the US election, questions have swirled over how US President-elect Donald Trump might approach the war, which has seen the US and Russia on opposing sides on many counts.

Central to the row is the question of which groups in the conflict are regarded as terrorist groups. The old Cold War enemies agreed to target ISIS, but the US has armed and supported what it calls moderate rebel groups to fight ISIS, many of which also oppose the regime of Syrian President Bashar al-Assad.

Assad told Portugal's RTP TV that Trump could be a "natural ally" to his government, but said he was dubious Trump could influence all the decision-makers to change the US strategy.

Trump has previously suggested that he is opposed to targeting the Assad regime and ISIS at the same time, and has said he is willing to work with Assad.

Syrian President Bashar al-Assad says Donald Trump could be a "natural ally."

"Of course, I would say this is promising. But can he deliver? Can he go in that regard? What about the countervailing forces within the administration? The mainstream media that were against him? How can he deal with it?" Assad said.

Members of the White Helmets rescue group search for victims after an airstrike on Aleppo on October 17.