Israeli airstrikes have pounded locations across the Gaza Strip, including parts of the south that Israel had declared safe zones.
It has heightened fears among more than two million Palestinians trapped in the territory that nowhere was safe.
In the nearly two weeks since Israel began attacking in response to a devastating Hamas rampage in towns across southern Israel, airstrikes have relentlessly hit the densely populated territory.
Even after Israel told Palestinians to evacuate the north and head to what it called “safe zones” in the south, strikes continued across the entire territory.
A residential building in Khan Younis, a city in southern Gaza where hundreds of thousands of Palestinians had sought shelter, was among the places hit.
Medical personnel at Nasser Hospital said they received at least 12 dead and 40 wounded.
The bombardments came after Israel agreed on Wednesday to allow Egypt to deliver limited humanitarian aid to Gaza, the first crack in a punishing 11-day siege.
The announcement of a plan to bring water, food and other supplies into Gaza happened as fury over the blast at Gaza City’s al Ahli hospital spread across the Middle East.
There were conflicting claims of who was behind the deadly hospital explosion.
Hamas officials in Gaza blamed an Israeli airstrike, saying hundreds were killed.
Israel denied it was involved and released a flurry of video, audio and other information that it said showed the blast was instead due to a rocket misfire by Islamic Jihad, another militant group operating in Gaza.
Islamic Jihad dismissed that claim.
US President Joe Biden, who visited Israel on Wednesday, said data from his defence department showed the explosion was not likely caused by an Israeli airstrike.
The White House later said an analysis of “overhead imagery, intercepts and open-source information” showed Israel was not behind the attack.
But the US continues to collect evidence.
Video from the scene showed the hospital grounds strewn with torn bodies, many of them young children.
Hundreds of wounded were rushed to Gaza City’s main hospital where doctors, already facing critical supply shortages, were sometimes forced to perform surgery on the floors, often without anaesthesia.
More than one million Palestinians have fled their homes, roughly half of Gaza’s population.
Many who fled the north and Gaza City, after Israel told them evacuate, have crowded into UN-run school shelters or the homes of relatives.
Following Thursday morning’s airstrikes, sirens wailed as emergency crews rushed to rescue survivors from a building where many residents were believed trapped under misshapen bed frames, broken furniture and cement chunks.
Gaza’s Hamas-led government said several bakeries in the territory were hit in the overnight strikes, making it even harder for hungry residents to get food.
The Israeli military said it killed a top Palestinian militant in Rafah, near the Egyptian border, and hit hundreds of targets across Gaza, including tunnel shafts, intelligence infrastructure and command centres.
It said it hit dozens of mortar launching posts, most of them immediately after they launched shells at Israel.
Palestinians have been launching barrages of rockets at Israel since the fighting began.
The Musa family fled to the typically sleepy central Gaza town of Deir al-Balah and took shelter in a cousin’s three-storey home near the local hospital.
But at 7.30pm on Wednesday, a series of explosions, believed to be airstrikes, rocked the building, turning the family home into a mountain of rubble that they said buried some 20 women and children.
The dead body of Hiam Musa, the sister-in-law of Associated Press photojournalist Adel Hana, was recovered from the wreckage on Wednesday evening, the family said.
They do not know who else is under the rubble.
“It doesn’t make sense,” Mr Hana said. “We went to Deir al-Balah because it’s quiet. We thought we would be safe.”
The Israeli military said it was investigating.
Israel has massed troops in the area and is expected to launch a ground invasion into Gaza, though military officials say no decision has been made.
The Gaza Health Ministry said 3,785 people have been killed in Gaza since the war began, and more than 12,500 wounded, mostly women, children and the elderly.
Another 1,300 people are believed buried under the rubble, health authorities said.
More than 1,400 people in Israel have been killed, mostly civilians slain during Hamas’s deadly incursion on October 7.
Roughly 200 others were abducted.
The Israeli military said on Thursday it has notified the families of 203 captives.
Violence between Israel and Hezbollah militants in Lebanon has also flared in recent days amid fears the fighting could spread across the region.
In the West Bank, where scores of Palestinians have been killed since the war started, 10 Palestinians have been killed over the last two days, nine by Israeli forces and one by a settler, according to the Palestinian Health Ministry.
Mr Biden said Egypt’s president agreed to open the Rafah crossing to let in an initial group of 20 lorries with humanitarian aid.
If Hamas confiscates aid, “it will end,” he said.
The aid will start moving Friday at the earliest, White House officials said.
Egypt must still repair the road across the border, which was cratered by Israeli airstrikes.
More than 200 lorries and some 3,000 tons (about 2,722 tonnes) of aid are positioned at or near the crossing, Gaza’s only connection to Egypt, said the head of the Red Crescent for North Sinai, Khalid Zayed.
Supplies will go in under supervision of the UN, Egyptian foreign minister Sameh Shoukry told Al-Arabiya TV.
Asked if foreigners and dual nationals seeking to leave would be let through, he said: “As long as the crossing is operating normally and the (crossing) facility has been repaired.”
It said Israel “will not thwart” deliveries of food, water or medicine from Egypt, as long as they are limited to civilians in the south of the Gaza Strip and do not go to Hamas militants.
The statement made no mention of fuel, which is badly needed for hospital generators.
Relatives of some of the people taken hostage and forced back to Gaza during the October 7 Hamas attack reacted with fury to the aid announcement.
“Children, infants, women, soldiers, men, and elderly, some with serious illnesses, wounded and shot, are held underground like animals,” said a statement from the Hostage and Missing Families Forum.
But “the Israeli government pampers the murderers and kidnappers”.
He also announced 100 US dollars (about £82.6 million) in humanitarian aid for Palestinians in Gaza and the West Bank.
King Abdullah II of Jordan planned to meet in Egypt with Egyptian President Abdel Fattah El-Sisi to discuss the conflict. The two countries have peace agreements with neighbouring Israel and are dealing with anger from their populations over the hospital blast.
British Prime Minister Rishi Sunak arrived in Israel on Thursday in a trip aimed at showing solidarity after the Hamas attack and preventing the war from escalating.
The people of Israel have “suffered an unspeakable, horrific act of terrorism and I want you to know that the United Kingdom and I stand with you”, he said on arrival.
