Officials in Hamas-run Gaza said on Monday dozens were killed overnight in "intense" Israeli bombardment, as the war which has sent shockwaves across the region passed the grim 100-day milestone.
Deadly violence in the Israeli-occupied West Bank and along Israel's border with Lebanon as well as fighting between US forces and Iran-backed Yemeni rebels in the Red Sea have raised fears of an escalation beyond the Gaza Strip.
The war, sparked by Palestinian attacks on Israel, 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, in what the group's media office described as "intense" strikes and artillery fire 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.
The Israeli military accuses Hamas militants of operating out of civilian facilities or from tunnels under them, a charge the Islamist 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.
The army said its forces had struck "two terrorists loading weapons into a vehicle" in Khan Yunis, southern Gaza's main city, and raided "a Hamas command centre" there and seized weapons.
The UN says more than three months of fighting have displaced roughly 85 percent of the territory'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.
Hamas's October 7 attack that triggered the war resulted in about 1,140 deaths in Israel, mostly civilians, according to an AFP tally based on official figures.
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 23,968 people in Gaza, mostly women and children, according to the territory's health ministry.
At central Gaza's Al-Aqsa hospital, bodies were piled on a donkey cart on Sunday.
Hisham Abu Suweh, waiting outside the emergency ward where his wife was being treated, said his family had thought they would be safe as civilians.
"We were sitting peacefully when the missile hit us," he said.
WHO chief Tedros Adhanom Ghebreyesus has said people in Gaza were "living in hell", echoing earlier UN warnings of a fast-approaching famine.
"Those with serious chronic conditions are dying due to the lack of care. Diseases are spreading among a population forced to crowd into ever smaller spaces, with little clean water or access to sanitation," Tedros said.
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.
Violence involving regional allies of Iran-backed Hamas -- considered a "terrorist" group by the United States and the European Union -- has surged since the war began.
In Yemen, the Huthis have vowed more attacks in solidarity with Gaza against what they deem Israeli-linked Red Sea shipping, despite US and British strikes against the Tehran-aligned rebels.
The US military said its fighter jets had shot down a cruise missile fired at the USS Laboon, an Airleigh Burke-class destroyer, off Hodeida in the southern Red Sea from Huthi-controlled areas of Yemen.
It appeared to be the first missile fired at a US warship by the Huthis since major US and British strikes on rebel-held Yemen on Friday.
These strikes followed growing attacks that have disrupted shipping in the vital Red Sea trade route.
On the Israel-Lebanon border, Israeli forces and Hamas ally Hezbollah have traded near daily fire.
A missile strike on Sunday killed two Israeli civilians, medics said, and three militants who had crossed in from Lebanon died in a gun battle, according to the army.
Hezbollah chief Hassan Nasrallah said Israel "has not achieved any real victory" in Gaza and will be forced to end the fighting and negotiate a diplomatic solution.
Diplomatic efforts to avoid escalation on Sunday included a visit by China's Foreign Minister Wang Yi to Egypt, where he called for "an international summit for peace" and Palestinian statehood.
In Turkey, a staunch supporter of the Palestinian cause, authorities have accused Israeli footballer Sagiv Jehezkel of "incitement" after he celebrated scoring a goal with a message written on a bandage on his left wrist, which read "100 days. 07/10".