United Nations secretary-general Ban Ki-moon has described a deadly attack on a UN school in southern Gaza as a moral outrage and a criminal act.
The attack hit the entrance of the facility in Rafah, which had been sheltering more than three thousand displaced people.
At least 10 were killed in the shelling and dozens wounded.
Mr Ban said the Israeli defence force has repeatedly been informed of the location of such sites.
Israel's military has not commented but has been carrying out renewed strikes in Gaza.
Gaza health officials say 30 people have died on Sunday, while militants continue to fire rockets into Israel.
