Israel has pounded the Gaza Strip from north to south in an expanded phase of its two-month-old war against Hamas after the United States wielded its United Nations Security Council veto to shield its ally from a global demand for a ceasefire.
Thirteen of the Security Council's 15 members voted for the resolution calling for an immediate humanitarian ceasefire that was blocked by Washington.
Since a truce collapsed last week, Israel has expanded its ground campaign into the southern half of the Gaza Strip by launching the storming of the main southern city Khan Younis.
Simultaneously, both sides have reported a major surge in fighting in the north.
Residents of Khan Younis said on Saturday Israeli forces were ordering people out of another district just west of positions the Israelis stormed earlier this week, suggesting a further assault could be imminent.
The vast majority of Gaza's 2.3 million residents have already been forced from their homes, many fleeing multiple times.
With fighting raging across the length of the territory, residents and UN agencies say there is now effectively nowhere safe to go, although Israel disputes this.
Decrying a "spiralling humanitarian nightmare", UN Secretary-General Antonio Guterres said on Friday nowhere in Gaza was safe for civilians.
Israel has blocked Gazans from fleeing along the main north-south route down the spine of the narrow strip and is shunting them instead towards the Mediterranean coast.
In Khan Younis, the dead and wounded arrived through the night at the overwhelmed Nasser hospital.
A medic ran out of an ambulance with the limp body of a small girl in a pink tracksuit.
Inside, wounded children wailed and writhed on the tile floor as nurses raced to comfort them.
Outside, bodies were lined up in white shrouds.
Nassar and another southern hospital, al Aqsa in Deir al-Ballah, reported 133 dead and 259 wounded between them in the past 24 hours, raising an official toll already at almost 17,500, with many thousands more missing and presumed dead.
There were no new figures on Saturday for dead and wounded from other parts of Gaza, including the entire northern half, where hospitals have ceased functioning and ambulances often can no longer reach the dead.
"We believe the number of martyrs under the rubble might be greater than those received at hospitals," health ministry spokesperson Ashraf al-Qidra told Reuters.
Fighting in the north has been its most intense in parts of Gaza City and settlements on its northern edge, where huge explosions could be seen from across the fence in Israel.
Israel launched its campaign to annihilate Gaza's Hamas rulers after the Iran-backed Islamist group's fighters burst across the Gaza border fence on October 7, killing 1200 people and capturing 240 hostages in a rampage through Israeli towns.
It says it is limiting harm to civilians by providing them with maps showing safe areas, and blames Hamas for causing civilian deaths by hiding among them, which the fighters deny.
Palestinians say Israel's campaign has turned into a scorched-earth war of vengeance against the entire population of an enclave as densely populated as London.
Washington has said it told Israel to do more to protect civilians in the next phase of the war than it did so far.
This week, Secretary of State Antony Blinken said there was a "gap" between Israel's promises to protect civilians and the outcome on the ground.
But Washington has continued to support Israel's insistence that a ceasefire would only benefit Hamas.
"We do not support this resolution's call for an unsustainable ceasefire that will only plant the seeds for the next war," Deputy US Ambassador to the UN Robert Wood told the Security Council before exercising Washington's veto.
Ezzat El-Reshiq, a member of Hamas' political bureau, condemned the US veto as "inhumane".
Israel's UN Ambassador Gilad Erdan said in a statement: "A ceasefire will be possible only with the return of all the hostages and the destruction of Hamas."
Australian Associated Press