United Nations Secretary-General Ban Ki-moon described a deadly attack on a UN school in Gaza as a "moral outrage and a criminal act" and called for those responsible for the "gross violation of international humanitarian law" to be held accountable.
In a statement, Mr Ban strongly condemned the shelling of the school in Rafah in southern Gaza that killed at least 10 civilians.
The school was sheltering 3,000 displaced persons and Ban said the "Israel Defense Forces have been repeatedly informed of the location of these sites."
The Israeli military said it was looking into the attack, the second to hit a school in less than a week.
There have been two days of quiet in Gaza. No rockets or missiles, no more destroyed houses, no more ambulance sirens screaming.
A three-year-old girl has been rescued from Gaza and brought to London for life-saving heart surgery.
A small team of NHS doctors and surgeons is travel to Gaza to set up facilities and establish how best to use specialists and equipment.