Deadly violence in the Israeli-occupied West Bank and along Israel's border with Lebanon as well as fighting between U.S. forces and Iran-backed Yemeni rebels in the Red Sea have raised fears of an escalation beyond the Gaza Strip.
The war, sparked by an attack on Israel by Hamas, has created a humanitarian catastrophe for the 2.4 million people in the besieged strip, the United Nations and aid groups warn, and reduced much of the territory to rubble.
The health ministry in Gaza, ruled by Hamas since 2007, reported more than 60 "martyrs" and dozens more wounded overnight, in what the group's media office described as "intense" Israeli bombardment across Gaza.
The Hamas government media office said two hospitals, a girls' school and "dozens" of homes were hit overnight.
Hospitals in Gaza have been hit repeatedly since the war erupted, and the World Health Organization, WHO, says most of them are no longer functioning.
Israel accuses Hamas of operating out of civilian facilities or from tunnels under them, a charge the militant group denies.
The latest strikes hit the southern cities of Khan Yunis and Rafah, as well as areas around Gaza City, the Hamas media office said.
Israeli military officials said their forces had struck "two terrorists loading weapons into a vehicle" in Khan Yunis, southern Gaza's main city, and raided "a Hamas command center" where they seized weapons.
The U.N. says more than three months of fighting have displaced roughly 85% of Gaza’s population, crowded into shelters and struggling to get food, water, fuel and medical care.
"There's no food, no water, no heating. We are dying from the cold," said Mohammad Kahil, displaced from northern Gaza to Rafah, on the southern border with Egypt.
The militants also seized about 250 hostages, 132 of whom Israel says remain in Gaza, including at least 25 believed to have been killed.
Vowing to destroy Hamas, Israel launched a relentless military campaign that has killed at least 24,100 people in Gaza, mostly women and children, according to the territory's health ministry.
WHO chief Tedros Adhanom Ghebreyesus has said people in Gaza were "living in hell," echoing earlier UN warnings of a fast-approaching famine.
In a joint statement on Sunday, the WHO, World Food Programme, WFP and UNICEF said, "a fundamental step change in the flow of humanitarian aid into Gaza is urgently needed."
The humanitarian organizations called for "safer, faster" supply routes to be opened, warning that the current levels of aid "fall far short of what is needed to prevent a deadly combination of hunger, malnutrition and disease."
The WFP said an aid convoy brought food to the territory's north on Thursday, the first such delivery since a one-week truce ended on December 1.
Cindy McCain, the UN agency's director, said: "People in Gaza risk dying of hunger just miles from trucks filled with food. Every hour puts countless lives at risk."
Israel has faced international pressure over surging civilian casualties in Gaza, and Prime Minister Benjamin Netanyahu is under intense domestic pressure to account for political and security failings surrounding the October 7 attacks.
On the war's 100th day on Sunday, hundreds of Israelis gathered in Tel Aviv for events urging action to rescue the remaining hostages.
"One hundred days and they are still abandoned there, 100 days and there is no sign of their return," said Amit Zach, a graphic designer.
A Hamas spokesman on Sunday said most of the hostages held in Gaza are likely to have been killed, blaming the Israeli leadership for their fate. The claim cannot be independently verified.
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