The Israeli military has forcefully rejected accusations that it was responsible for the deaths of 15 people at a UN school in Beit Hanoun in Gaza.

A spokesperson for the IDF said: “The inquiry and the documented footage presented here concluded that a single errant IDF mortar landed in the courtyard of the UNRWA school, when it was completely empty.”

The army said that the mortar was fired in response to Hamas militants operating next to the UN school.

“The militants fired anti-tank missiles at IDF soldiers, who then responded by firing several mortars in their direction,” they said.

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.