France and Turkey have called the bombing of two schools and five hospitals in Syria "war crimes", while hopes for a ceasefire faded as President Bashar al-Assad played down prospects of a truce.
Up to 50 civilians, including children, died when missiles hit at least five medical buildings and two schools in the Aleppo and Idlib provinces on Monday.
UN Secretary General Ban Ki-moon said the raids violated international law and "cast a shadow" over efforts to end Syria's five-year civil war. He did not say who was responsible for the attacks but groups monitoring the conflict suspected the strikes were carried out by Russia, an ally of the Syrian regime.