The UN High Commissioner for Human Rights Volker Turk warned on Saturday there was the potential for thousands more civilians to die if Israel presses a major ground offensive in Gaza.
Israel's army relentlessly struck the territory on Saturday after fierce overnight bombardment that rescuers said destroyed hundreds of buildings three weeks into the war, which was sparked by a Hamas attack on southern Israel on October 7 which killed 1,400 Israelis.
"Given the manner in which military operations have been conducted until now, in the context of the 56-year-old occupation, I am raising alarm about the possibly catastrophic consequences of large-scale ground operations in Gaza and the potential for thousands more civilians to die," Turk said.
"There is no safe place in Gaza and there is no way out. I am very worried for my colleagues, as I am for all civilians in Gaza."
The health ministry in Gaza said Israel's bombardment of the Gaza Strip had killed 7,703 people, mainly civilians, including 3,195 children. Israel has also imposed a total siege of the strip cutting off fuel, water and electricity.
On Friday, Israel imposed a communications blackout on Gaza, leading rights groups to warn that atrocities could be committed under the cover of darkness.
"Compounding the misery and suffering of civilians, Israeli strikes on telecommunications installations and subsequent Internet shutdown have effectively left Gazans with no way of knowing what is happening across Gaza and cut them off from the outside world," Turk said.
"Ambulances and civil defence teams are no longer able to locate the injured, or the thousands of people estimated to be still under the rubble.
"When these hostilities end, those who have survived will face the rubble of their homes and the graves of their family members," Turk said.
He called on all parties "to do all in their power to de-escalate the conflict."
The conflict is the fifth and deadliest in Gaza since Israel unilaterally withdrew from the Palestinian territory in 2005.
The latest Israeli strikes on Gaza were the most intense since the war broke out. They coincided with ground operations.
"Continued violence is not the answer. I call on all parties as well as third States, in particular those with influence over the parties to the conflict, to do all in their power to de-escalate this conflict," Turk added.