At least 14 patients and doctors were killed in an air strike on Wednesday on an Aleppo hospital supported by Medicins Sans Frontieres (MSF) and the International Committee of the Red Cross, as the United Nations (UN) called on Russia and the United States to save the failing peace talks.
The attack hit Al-Quds hospital in the city's southern al-Sukkari neighborhood. Medical staff and three children were reportedly among the dead, including Dr. Wasem Maaz, one of the last pediatricians in the opposition-held part of the city.
Another doctor who knew Maaz described him to VICE News as incredibly kind and friendly, adding that his brother was an orthopedic surgeon in Aleppo.
MSF said at least 14 people had been killed but that number was expected to rise. Aleppo's branch of the Syrian Civil Defense, a volunteer search and rescue group known as the White Helmets, said 30 people were killed, including the pediatrician, a dentist, a nurse, and three volunteers. Ten people were still under rubble and 60 were injured, it said.
Russia on Thursday denied its planes carried out the strikes and the country's defense ministry suggested another country was responsible.
"According to our information, on the evening of April 27, for the first time after a long break, there was a plane over Aleppo that belonged to one of the so-called anti-Islamic State coalition countries," it said in a statement.
Video and images of the aftermath showed bloodied and charred bodies being pulled from the rubble.
A new wave of aerial bombing on Thursday on rebel-held districts of the city killed at least 30 more civilians, a rescue worker said. SOHR put the toll at least 20.
In government-held areas, rebel mortar shelling killed at least 14 people, SOHR and Syria's state news agency SANA reported.
Syrian government airstrikes and shelling by armed groups have killed dozens of civilians in Aleppo over the past few days, rescue workers and monitoring groups say, as the city suffers a marked escalation in violence. SOHR said air strikes on rebel-held areas of Aleppo had killed 91 citizens in the past six days while rebel shelling of government-held areas had claimed 49 lives.
The increase in fighting has left a cessation of hostilities agreement in tatters and comes after the virtual collapse of UN-brokered peace talks in Geneva last week.
"Wherever you are, you hear explosions of mortars, shelling and planes flying over," Valter Gros, who heads the ICRC office in Aleppo, said in a statement.
"There is no neighborhood of the city that hasn't been hit. People are living on the edge. Everyone here fears for their lives and nobody knows what is coming next," he said.
On Thursday the UN mediator called on the leaders of the United States and Russia to salvage the "barely alive" two-month-old ceasefire in Syria and revive the peace process which began in Geneva February.
Special Envoy Staffan de Mistura voiced deep concern at the truce unraveling in Aleppo and at least three other hotspots, although he saw some closening of positions between the government and opposition visions of political transition.
"Hence my appeal for a US-Russian urgent initiative at the highest level, because the legacy of both President Obama and President Putin is linked to the success of what has been a unique initiative which started very well. It needs to end very well," de Mistura told a news conference.
The US and Russia must convene a ministerial meeting of major and regional powers who compose the International Syria Support Group, he argued. When both countries had such political capital invested in a Syria success story, and had a common interest in not seeing Syria end up in another cycle of war, they should be able to revitalize the peace process they have created "which is still alive but barely," he said.
The main opposition group in Geneva, the High Negotiations Committee (HNC), pulled out of the formal talks a week ago in protest of intensified fighting and slow aid deliveries.
"How can you have substantial talks when you have only news about bombing and shelling? It's something that even I find it difficult, can you imagine the Syrians?" de Mistura said, adding he aimed to resume talks in May, though he gave no date.
The peace talks had brought about a major, but not complete halt in violence, after a cessation of hostilities was announced February 26 — but violence has since escalated.
The White Helmets said bombings had left at least 89 civilians dead and injured another 135 in the city since April 22, Human Rights Watch reported on Wednesday — before the latest air strikes.
It is unclear whether the strikes are being carried out by government forces or allied Russian aircraft, which began an extensive bombing campaign on rebel-held areas in September. Rebel groups and Islamic factions are also shelling regime-held neighborhoods.
A surgeon working in Aleppo treating victims of the strikes told VICE News there had been heavy bombings in a number of areas of the city this week, with most taking place in late morning, and that he and his team had been treating victims for hours afterwards each day.
HRW said the strikes appeared not to have targeted military objectives, which could make them war crimes. It urged the international community to move to protect Syria's civilians.
"With the civilian death toll rising and hundreds of thousands of people fleeing the country, key powers need to be focused on protecting civilians in all parts of Syria," said Nadim Houry, HRW's deputy Middle East director. "There are decisive measures that key powers, particularly those on the [United Nations] Security Council, can take to deter abusive parties and improve protection for civilians."