According to initial reports, the school was destroyed, collapsing on top of Palestinians who took shelter inside from the intense bombardment by Israeli air and ground forces.

Ma’an’s reporter said that dozens more, all civilians, were injured in the attack on the Al-Fakhoura School. The death toll is expected to rise as a number of the wounded are said to be in critical condition. Ambulances have been unable reach the site of the killing.

Children are also said to be among the dead.

The school is operated by UNRWA, the UN's agency for Palestinian refugees. UNRWA has been using its schools to house some of the 15,000 Gazans who have fled their homes due to Israel's ground invasion of the Gaza Strip, which began on Saturday.

Jabaliya Refugee Camp has been the site of some of the most intense fighting between Israeli forces and Palestinian fighters.

Earlier on Tuesday, the United Nations confirmed that three refugees had been killed at 11:30 on Monday night when Israeli forces fired directly on a UNRWA school in Gaza City. Another UNRWA school also came under fire in the city of Rafah.

"There's nowhere safe in Gaza. Everyone here is terrorized and traumatized," said John Ging, the top UN official in Gaza, blaming the international community for allowing the Israeli invasion to continue.

"I am appealing to political leaders here and in the region and the world to get their act together and stop this," he said, speaking at Gaza's largest hospital. "They are responsible for these deaths."