The 24-hour death toll was the worst in a week and added to the massive fatalities from the nearly two-year war that has shattered the enclave housing more than 2 million Palestinians.

An airstrike on Gaza City killed at least 12 people as the conflict entered a new phase with an Israeli offensive to rid the city of Hamas and free hostages.

Gaza City has come under intense air attack, the territory's Hamas-run civil defence agency has said, as Israeli forces prepare to occupy the city. Mahmud Bassal, a spokesman, said the residential areas of Zeitoun and Sabra had for three days been hit by bombs and drone strikes that "cause massive destruction to civilian homes",