At least 96 children have been killed and 223 injured in the continuous bombing of Syria’s Aleppo city since Friday, the United Nations Children’s Fund said Wednesday. A senior UNICEF official said that the children are stuck in a “living nightmare.”

“There are no words left to describe the suffering they are experiencing,” UNICEF Deputy Executive Director Justin Forsyth said in a statement. “Nothing can justify such assaults on children and such total disregard for human life.”

He described the children’s suffering as “definitely the worst we have seen.”

Syria’s health system is also “crumbling,” UNICEF said in the statement. There are fewer than 30 doctors tending the several hundred injured every day in Aleppo in war-torn Syria. Warplanes put two hospitals out of action in one of the rebel-held areas of Aleppo on Wednesday. A siege has trapped nearly 250,000 people in the city with food running out and cutting off their access to humanitarian aid.

“The warplane flew over us and directly started dropping its missiles ... at around 4 a.m.,” Mohammad Abu Rajab, a radiologist at the largest trauma hospital in Aleppo’s rebel-held area, told Reuters. “Rubble fell in on the patients in the intensive care unit.”

United Nations Secretary-General Ban Ki-moon asked the Security Council on Wednesday to step up its efforts in dealing with the worsening situation in Syria. “I urge you to overcome your divisions and meet your responsibilities to prevent and reduce conflict and to build peace and stability,” he said.

According to Physicians for Human Rights, 95 percent of medical personnel who were in Aleppo before the ongoing war began have either fled, been detained or were killed. “Those using ever more destructive weapons know exactly what they are doing. They know they are committing war crimes,” Ban said.

“Attacks and access restrictions on medical care are signs of a broader erosion of respect for international humanitarian law.  Failure to act is an affront to our shared humanity.  It undermines States’ legal obligations and the multilateral system as a whole,” the secretary-general said.

“Imagine a slaughterhouse. This is worse. Even a slaughterhouse is more humane,” he added.

Pope Francis described Aleppo “an already martyred city, where everybody is dying.” Speaking from St. Peter's Square in Rome on Wednesday, the pope called on all sides to “protect civilians.”

“This is an imperative and urgent obligation. I appeal to the consciences of those responsible for the bombings, who will one day will have to account to God,” he said.