The Israeli army struck seven UN schools, where Palestinians were sheltering from attacks, killing at least 44, a UN inquiry has found.
According to the UN, at least 2,189 Palestinians died during the 50 day conflict, of which at least 1,486 were civilians.
An independent board of inquiry looked into incidents at ten schools run by the UN, finding that one girls' school was hit by 88 rounds of mortar fire with other schools hit by missiles and anti-tank projectiles.
At another girls' school, the inquiry found, "no prior warning had been given by the government of Israel of the firing of 155mm high explosive projectiles on, or in the surrounding area of the school".
"It is a matter of the utmost gravity that those who looked to them for protection and who sought and were granted shelter there had their hopes and trust denied," UN Secretary General Ban Ki-moon wrote in a cover letter accompanying the summary.
"United Nations premises are inviolable and should be places of safety, particularly in a situation of armed conflict," he said. "I will work with all concerned and spare no effort to ensure that such incidents will never be repeated."
A spokesman for the Israeli foreign ministry, Emmanuel Nahshon, said: "All of the incidents attributed by the report to Israel have already been subject to thorough examinations, and criminal investigations have been launched where relevant."
"Israel makes every effort to avoid harm to sensitive sites, in the face of terrorist groups who are committed not only to targeting Israeli civilians but also to using Palestinian civilians and UN facilities as shields for their terrorist activities."
The inquiry also found three empty UN schools were used by Hamas to store weapons.