A United Nations official has said Israel is carrying out "collective punishment" on the citizens in Gaza.
Philippe Lazzarini, the head of the UN agency for Palestinian refugees UNRWA, told an emergency meeting on Monday that women and children cannot be "collateral damage".
He said an immediate humanitarian ceasefire is "a matter of life and death for millions".
Mr Lazzarini said the level of destruction across Gaza "is unprecedented, the human tragedy unfolding under our watch is unbearable."
Despite half the population of Gaza being told to evacuate south by Israeli authorities, significant numbers of Gazans have been killed as they sought shelter.
"I have said many times and I will say it again: no place is safe in Gaza", Mr Lazzarini said.
This "forced displacement" has left more than 670,000 in overcrowded UNRWA schools and basements, he said.
Woman and children
Mr Lazzarini said that nearly 70% of those reported killed are children and women.
"Save the Children reported yesterday that nearly 3,200 children were killed in Gaza in just three weeks," he said.
"This surpasses the number of children killed annually across the world's conflict zones since 2019.
“This cannot be collateral damage,” he stressed, adding that Israel is carrying out "collective punishment".
'Population being dehumanised'
Mr Lazzarini said Israel must abide by the rules of war.
"Today, Gazans feel that they are not treated as other civilians," he said.
"Most of them feel trapped in a war they have nothing to do with - they feel the world is equating all of them to Hamas.
"This is dangerous. And we know this too well from previous conflicts and crises.
"An entire population is being dehumanised.
"The atrocities of Hamas do not absolve the State of Israel from its obligations under International Humanitarian Law.
"Every war has rules, and this one is no exception."
UNRWA 'only glimmer of hope'
Mr Lazzarini outlined a dire humanitarian situation in the Gaza Strip, with medicines, food, water and fuel running out, adding that panic pushed thousands of desperate people to UNRWA aid warehouse and distribution centres.
“A further breakdown in civil order will make it extremely difficult, if not impossible, for the largest UN agency in Gaza to continue operating. It will also make it impossible to bring in convoys,” he said.
Mr Lazzarini highlighted the deep impact of the crisis on the staff of his agency, 64 of whom have been killed since October 7th.
“My UNRWA colleagues are the only glimmer of hope for the entire Gaza Strip, a ray of light as humanity sinks into its darkest hour,” he said.
He also emphasized that the "handful of convoys" being allowed through the Rafah crossing is "nothing compared to the needs" of over two million people trapped in the enclave.
“The system in place to allow aid into Gaza is geared to fail unless there is political will to make the flow of supplies meaningful, matching the unprecedented humanitarian needs,” he said.
Fatalities highest since records began
Mr Lazzarini reiterated that while the focus is on Gaza, "another crisis is unfolding in the West Bank including East Jerusalem."
"The United Nations has been sounding the alarm for months on the increased violence," he said.
"Palestinian fatalities this year are the highest since the UN started to keep records in 2005.
"At least 115 Palestinians have been killed since October 7th, including 33 children.
"The movement restrictions imposed across the West Bank are impacting our services, including schools and health centres.
"Meanwhile, the situation on the Israeli Lebanese border is getting worse, with regular exchanges of fire and civilian casualties reported," he added.
Israeli bombardment is continuing following Hamas' attacks earlier this month.