GAZA CITY: At least 10 people were killed in a fresh strike on a UN school in southern Gaza which was sheltering Palestinians displaced by an Israeli military offensive, taking Sunday's death toll to 21, medics said.

Gaza emergency services spokesman Ashraf al-Qudra said dozens of people were wounded in the attack which took place in the southern city of Rafah, which straddles the border with Egypt.

Chris Gunness, spokesman for the UN agency for Palestinian refugees (UNRWA), said the school had been housing thousands of internally displaced people (IDPs) who had been forced to flee their homes by the ongoing violence in Gaza.