An Israeli airstrike hit a hospital in southern Gaza on Sunday night, leaving a part of the hospital in flames and causing multiple casualties, two doctors working at Nasser Medical Complex told CNN,

Officials in Hamas-ruled Gaza say the new Israeli assault has killed more than 400 people, as Israel accuses Hamas of refusing to extend the ceasefire.

The Gaza Health Ministry said the strike hit the surgery department at Nasser ... Israel’s Defence Minister Israel Katz confirmed the target was Barhoum. The military did not name the target, which it described only as “a key terrorist” in Hamas.

The military sent ground troops into part of the southern city of Rafah as thousands of Palestinians heeded evacuation orders on Sunday.

Israel previously threatened Gaza with "complete destruction and devastation"​ if Hamas didn't hand over the remaining hostages.

The world body will temporarily remove about a third of its approximately 100 international staffers working in Gaza.

Israel on Saturday launched two waves of airstrikes against Hezbollah in the morning and night in response to a rocket attack on Metula, with Lebanese media reporting at least seven people killed.