Israel battled Hamas fighters in the Gaza Strip's biggest cities on Thursday and said it had attacked dozens of targets, leaving 350 Palestinians dead and the rest struggling to survive in rapidly shrinking areas of refuge.
Gazans crammed into Rafah on the southern border with Egypt, heeding Israeli leaflets and messages saying that they would be safe in the city after successive warnings to head south.
But more than 20 people were killed in apartments there late on Wednesday sheltering displaced civilians from the north, said Eyad al-Hobi, a relative of some of those killed.
"All apartments in the building suffered serious damage," he said as people brought out two apparently lifeless children.
In southern Gaza's largest city, Khan Younis, Israel said its forces killed a number of Hamas fighters. Residents reported several Israeli air strikes and non-stop tank fire in the city's east.
In Washington, a senior State Department official said, US Secretary of State Antony Blinken spoke with Israel's strategic affairs minister on Thursday, and told him Israel needs to do more to protect civilians in its offensive in southern Gaza.
Israeli troops reached the heart of Khan Younis on Wednesday in a new phase of the war, now entering its third month. Health officials said three people were killed there on Thursday.
Ambulances and relatives rushed the wounded into the city's Nasser hospital, but even the floor space inside was full. Two badly wounded children lay on a trolley and a bloodstained young boy lay screaming among the patients on the floor.
The UN Palestinian Refugee Agency (UNRWA) said 1.9 million people – 85% of Gaza's population - had been displaced and its shelters were four times over capacity.
UN refugee chief Filippo Grandi said pressure was growing in the south of the enclave near Egypt.
Egypt said it would not allow Gazans to be pushed across its border. Diaa Rashwan, head of the State Information Service, added that Egypt believed Israel was also trying to force Palestinians in the West Bank towards Jordan.
The Gaza health ministry said 17,177 Palestinians had been killed and 46,000 wounded since October 7. In the past 24 hours alone, 350 people had been killed, ministry spokesman Ashraf Al-Qidra said.