UN aid deliveries to Gaza were suspended on Friday due to shortages of fuel and a communications shut down, deepening the misery of thousands of hungry and homeless Palestinians as Israeli troops battled Hamas militants in the enclave.
The United Nations' World Food Program (WFP) said civilians faced the "immediate possibility of starvation" due to the lack of food supplies.
International officials say a humanitarian crisis for the 2.3 million residents of Gaza is entering a new, more dire phase as war enters its seventh week.
Israel has vowed to annihilate the Hamas militant group that controls Gaza, since its fighters killed 1,200 people and dragged away 240 hostages on a deadly rampage on Oct. 7.
Since then, Israel has bombed much of Gaza to rubble, ordered the depopulation of the entire northern half of the enclave and made around two-thirds of Gazans homeless.
Gaza health authorities deemed reliable by the United Nations say more than 11,500 people are confirmed dead, 40% of them children, with many others trapped under rubble. They have not been able to update that toll for several days because of a lack of communications.
At Gaza's biggest hospital Al Shifa, focus of international alarm this week as a primary target of Israel's ground assault, Israel said its forces had found a vehicle with a large number of weapons, and an underground structure it called a Hamas tunnel shaft, after two days searching the premises.
The army released a video it said showed a tunnel entrance in an outdoor area of the hospital, littered with concrete and wood rubble and sand. It appeared the area had been excavated. A bulldozer appeared in the background.
The army also said it had found the bodies of two hostages in buildings near, though not inside, the hospital grounds.
Israel has long maintained that the hospital sat above a vast underground bunker housing a Hamas command headquarters. Hospital staff say this is false and that Israel's findings there have so far established no such thing.
Hamas denies using hospitals for military purposes. It says some hostages have received treatment at medical centers but they have not been held inside them.
Al Shifa staff said a premature baby died at the hospital on Friday, the first baby to die there in the two days since Israeli forces entered.
Three had died in the previous days while the hospital was surrounded.
Israel had said it would send help including incubators to rescue 36 babies being kept eight-to-a-bed to keep warm since the neo-natal ward was knocked out last week. But staff said the Israelis allowed in no meaningful aid for the babies or hundreds of other patients and thousands of displaced people trapped inside the compound while Israeli commandos search it.
Five babies were in a very serious condition, Al Shifa hospital compound director Muhammad Abu Salmiya told Al Jazeera.
"We are trying to keep them alive, wrapping them in cellophane, putting bottles of hot water near them to keep them alive, our attempts are what is keeping them alive."
Communication with outside organizations had been cut and pleas to evacuate those in most desperate condition had gone unanswered, he said.
"There is nothing in the hospital except more dead bodies, there isn't any kind of life necessities in the hospital, no electricity, no water, no oxygen, no food. The Israeli army is wandering around freely in the hospital. The hospital is besieged from everywhere, tanks surround us from everywhere."
The last hospital fully functioning in the northern half of Gaza, Al Ahli, was forced to close its surgery department after it ran out of anesthetics. British-Palestinian surgeon Ghassan Abu Sitta, who escaped on foot to the south, told Reuters he had decided to leave because he was now powerless to help patients.
"It has been a living nightmare - leaving 500 wounded knowing that there's nothing left for you to be able to do for them, it's just the most heartbreaking thing I ever had to do," Abu Sitta said by phone.
Homes destroyed
With the war about to enter its seventh week, there was no sign of any let-up despite international calls for a ceasefire or at least for humanitarian pauses.
Israel's military, which has concentrated its assault on northern Gaza, said its troops and war planes were keeping up pressure on Friday.
Overnight they took control of an Islamic Jihad commander's stronghold, the military said, and also killed Hamas fighters inside a school where they found a large number of weapons.
The UN Office for the Coordination of Humanitarian Affairs (OCHA), quoting Palestinian data, said Israeli attacks had destroyed or damaged at least 45% of Gaza's housing units.
The United Nations said there would be no cross-border aid operation on Friday due to fuel shortages and a communication shutdown. For a second consecutive day no aid trucks arrived in Gaza due to lack of fuel for distributing relief.
An Israeli official said later on Friday that Israel's war cabinet had approved letting in two fuel trucks a day into Gaza to help meet UN needs, following a US request.
Humanitarian crisis
Nearly the entire Gazan population is in desperate need of food assistance, said WFP Executive Director Cindy McCain.
"With winter fast approaching, unsafe and overcrowded shelters, and the lack of clean water, civilians are facing the immediate possibility of starvation," she said in a statement.
A UN human rights official said Israel must allow water and fuel into Gaza to restart the water supply network otherwise people would die of thirst and disease. Israel's actions were a breach of international law, Pedro Arrojo-Agudo said.
The World Health Organization said it feared the spread of disease, including respiratory infections and diarrhea.
The Israeli military's chief of staff said Israel was close to destroying Hamas' military system in the north of the coastal enclave.
In the Israeli-occupied West Bank, Hamas' Al-Quds Brigades said they had engaged Israeli forces for several hours in the city of Jenin overnight.
Israel's military said war planes struck militants in Jenin who had opened fire on Israeli soldiers and at least five militants were killed.
At least 178 Palestinians have been killed in the West Bank since Oct. 7. The violence there has underscored fears that the territory, seized by Israel in the 1967 Middle East War, could spiral out of control in tandem with the conflict in Gaza.
