The United Nations Children's Fund (UNICEF) reports that no fewer than 22 children and six teachers have become victims of an air strike on a school in Syria's Idlib province.
"This is a tragedy. This is an outrage. If it was done intentionally, it's a war crime," said Anthony Lake, executive director at UNICEF.
Lake also claimed that the school had been targeted several times. Human rights activists in opposition-controlled Idlib believe Russia's air force might have been behind the attack.
Vitaly Churkin, Russia's permanent representative to the UN, has already commented on the incident.
"The easiest thing to say is that it wasn't us," Churkin said. "But I'm a responsible person; we have to wait and see what our Defense Ministry has to say about this."
"It's terrible, terrible — I hope this was not us," he added.