There was little shelter and barely any services in al-Mawasi when the Abu Hatab family arrived seeking sanctuary from the intensifying bombardment around their homes in Khan Yunis.

But al-Mawasi was the one place they had been told they would be safe. From early November Israel urged the civilian population of Gaza evacuate to the narrow, sandy coastal strip the size of Heathrow airport.

On Wednesday night, the bombardment followed them to the so-called safe zone, when shelling rained down on their flimsy tents as they slept.

"They dropped leaflets and told us to come here, that this was truly the one safe place," Bahaa Abu Hatab, one of the survivors said. "My brother took his children to protect them from the occupation's missiles, but here they were martyred anyway, in this 'safe' place, in the tent that my brother set up in this field."

At least 14 Palestinians, including nine children, were killed in strikes on al-Mawasi early on Thursday, according to the Hamas-run ministry of health in Gaza.