Medical charity Médecins Sans Frontières has claimed the most recent bombing in Syria was designed to kill civilians.
The UN says the situation in the Syrian city of Aleppo is catastrophic.
Air strikes on and around the al-Quds hospital have killed at least 27 people, while more than 30 died in other attacks.
The director of MSF in Ireland Jane-Ann McKenna said she had been getting eyewitness accounts of the hospital bombing.
"The people who were there described to us how it was a series of three bombs. Two attacked the buildings surrounding the hospital and as the wounded were being brought to the hospital, the final bomb landed at the entrance to the emergency room (of the hospital)," she said.
"The objective was very clearly to try to inflict the maximum number of casualties on the civilian population."