About 50 civilians were killed when missiles hit five medical centers and two schools in rebel-held Syrian towns on Monday, the United Nations and residents said.
The carnage occurred as Russian-backed Syrian troops intensified their push toward the rebel stronghold of Aleppo.
Fourteen people were killed in the town of Azaz near the Turkish border when missiles slammed into a school sheltering families fleeing the offensive and a children's hospital, two residents and a medic said.
Bombs also hit another refugee shelter south of the town and a convoy of trucks, another resident said.
"We have been moving scores of screaming children from the hospital," medic Juma Rahal said.
At least two children were killed and scores of people injured, he said.