Unlike precision-guided missiles usually fired from aircraft, mortar shells typically do not have guidance capabilities and are far less accurate than other munitions.
Chris Guiness from the UN Relief and Works Agency, the UN body responsible for running the school, said no Hamas members were present at the time of the Israeli mortar strike.
“There is absolutely no evidence that there were Hamas rockets or personnel in the school, or that Hamas were firing rockets from the school,” he said.
UN Secretary General Ban Ki-moon said after the incident that he was “appalled” and confirmed that UN staff were among the casualties.