While the exact death toll remains to be confirmed, initial news reports indicate that the number of casualties could be well above 60, with dozens severely injured. Most of the children were reported to be aged between 10 and 13.

In his  statement, the UN chief called "on all parties to respect their obligations under international humanitarian law, in particular the fundamental rules of distinction, proportionality and precautions in attack," emphasising that all parties must take "constant care to spare civilians and civilian objects in the conduct of military operations".

The Secretary-General called for an "independent and prompt investigation" into this incident and extended his "deepest condolences" to the families of the victims.

The Head of the UN Children’s Fund (UNICEF) also strongly condemned the incident and urged the warring parties and international community "to do what’s right for children and bring an end to this conflict". 

“Attacks on children are absolutely unacceptable,” she said UNICEF Executive Director Henrietta Fore  on Twitter. “I’m horrified by the reported airstrike on innocent children, some with UNICEF backpacks. Enough is enough.”

UNICEF/Clarke for UNOCHA