At least 19 Palestinians who were sheltering in a UN-run school in Gaza have been killed after it was shelled on Wednesday.
More than 90 people were injured.
Most had taken shelter after being told by the Israeli army to move from their homes to somewhere safer.
The UN has accused Israel of attacking the school, despite being told several times that it was housing civilians.
United Nation relief and works agency (UNRWA) spokesperson Christopher Robert Gunness said Israeli forces had broken international law.
“We have visited the site and gathered evidence. We have analysed fragments, examined craters and other damage. Our initial assessment is that it was Israeli artillery that hit our school in which 3,300 people had sought refuge. We believe there were at least three impacts. We condemn in the strongest possible terms the serious violation of international law by Israeli forces”.
Lieutenant Colonel Peter Lerner, spokesperson for the Israeli Defence Force said the army had fired in response to militants: “In the morning there was mortar fired right from next to the school, there was an exchange of fire with our forces. We are currently reviewing the results of that and looking into other options as well. Clearly it’s a tragedy, but the IDF does not intentionally target UN premises.”
More than 1,200 Palestinians, most of them civillians, have been killed in the last three weeks. Fifty-three Israeli soldiers have been killed as well as three civilians.