Israel pressed its offensive against Hamas militants in Gaza on Saturday after the United States blocked an extraordinary UN bid to call for a ceasefire in the two-month war.
Hamas and the Palestinian Authority swiftly condemned the US veto as Gaza's health ministry put the latest death toll in Gaza at 17,487 people, mostly women and children.
An Israeli strike on the southern city of Khan Yunis killed six people, while five others died in a separate attack in Rafah, the ministry said Saturday.
Israel has vowed to eradicate Hamas over its unprecedented attack on October 7.
Vast areas of Gaza have been reduced to rubble and the UN says about 80 percent of the population has been displaced, with dire shortages of food, fuel, water and medicine reported.
"It's so cold, and the tent is so small. All I have are the clothes I wear, I still don't know what the next step will be," said Mahmud Abu Rayan, displaced from Beit Lahia in the north, AFP reported.
A UN Security Council resolution that would have called for an immediate ceasefire was vetoed by the United States on Friday.
US envoy Robert Wood said the resolution was "divorced from reality" and "would have not moved the needle forward on the ground".
Israeli Foreign Minister Eli Cohen said the ceasefire "would prevent the collapse of the Hamas terrorist organization, which is committing war crimes and crimes against humanity, and would enable it to continue ruling the Gaza Strip".
Hamas slammed on Saturday the US rejection of the ceasefire bid as "a direct participation of the occupation in killing our people and committing more massacres and ethnic cleansing".
Palestinian Prime Minister Mohammed Shtayyeh said it was "a disgrace and another blank cheque given to the occupying state to massacre, destroy and displace".
The veto was swiftly condemned by humanitarian groups, with Doctors Without Borders (MSF) saying the Security Council was "complicit in the ongoing slaughter".
Israel's military said Friday it had struck 450 targets in Gaza over 24 hours, showing footage of strikes from naval vessels in the Mediterranean.
The Gaza health ministry reported 40 dead near Gaza City in the north, and dozens more in Jabalia and the main southern city of Khan Yunis.
Following two months of conflict and bombardment, UN chief Antonio Guterres said Friday "the people of Gaza are looking into the abyss".
"People are desperate, fearful and angry," he said.
"All this takes place amid a spiralling humanitarian nightmare."
Many of the 1.9 million Gazans who have been displaced by the war have headed south, turning Rafah near the Egyptian border into a vast camp.
Only 14 of the 36 hospitals in the Gaza Strip were functioning in any capacity, according to United Nations' humanitarian agency OCHA.
With the civilian toll mounting, US National Security Council spokesman John Kirby told reporters Friday that Washington believes Israel needs to do more to protect civilians in the conflict.
"We certainly all recognize more can be done to... reduce civilian casualties. And we're going to keep working with our Israeli counterparts to that end," he said.
The death toll also rose in the Israeli-occupied West Bank, where Israeli forces shot dead six Palestinians on Friday, the territory's health ministry said.
Israel said Friday it has lost 91 soldiers in Gaza.
It said two others were wounded in a failed bid to rescue hostages overnight, and that "numerous terrorists" were killed in the operation.
Hamas claimed a hostage was killed in the operation, and released a video purporting to show the body, which could not be independently verified.
Hamas rocket parts, launchers and other weapons as well as a one-kilometre tunnel were found at Al-Azhar University in Gaza City, the army said, as it warned residents to move west.
An attack on the US embassy in Iraq on Friday deepened fears of wider regional conflict.
Salvoes of rockets were launched against the mission in Baghdad's heavily fortified Green Zone, adding to dozens of recent rocket and drone strikes by pro-Iran groups against American or coalition forces in Iraq and Syria.
