Gaza, Strip, Palestinian Territories: Hamas said Sunday its fighters were engaged in "heavy fighting" in Gaza where Israel has escalated ground operations, while the UN said desperate Palestinians burst into aid centres after weeks of siege and bombardment.
World leaders underlined the urgency of delivering aid to the Hamas-run territory and protesters worldwide rallied for a ceasefire, after Israeli Prime Minister Benjamin Netanyahu steeled his nation for a "long and difficult war".
Despite calls for a humanitarian truce, international outrage and the potential risk to hostages held in Gaza, Israel has intensified the war triggered by Hamas's unprecedented attack.
Hamas militants stormed across the Gaza border on October 7 in the deadliest attack in Israel's history, killing 1,400 people, mostly civilians, and kidnapping 230 others, according to Israeli officials.
The health ministry in Gaza says the retaliatory Israeli bombardment has killed more than 8,000 people, mainly civilians and half of them children.
Panic and fear have surged inside the Palestinian territory, where the UN says more than half of its 2.4 million residents are displaced and thousands of buildings destroyed.
Hamas's armed wing, the Ezzedine al-Qassam Brigades, said on Sunday its "fighters are currently engaged in heavy fighting with machine-guns and anti-tank weapons with the invading occupation (Israeli) forces in northwest Gaza".
Israel's army said a new "stage" of the war started with ground incursions since late Friday, an escalation from two brief operations earlier in the week.
British Prime Minister Rishi Sunak and French President Emmanuel Macron "stressed the importance of getting urgent humanitarian support into Gaza" during a conversation on Sunday, the UK government said.
UN chief Antonio Guterres said the situation was "growing more desperate by the hour" as casualties increase and essential supplies of food, water, medicine and shelter dwindle.
The Palestinian Red Crescent Society said Sunday Israel was repeatedly bombing around Al-Quds hospital in central Gaza, causing damage and putting civilians at risk.
Mohamed al-Talmas, who has taken shelter in Gaza's biggest hospital Shifa, said "the ground shook" with intense Israeli raids.
"No one knew where they (strikes) were coming from - north, south, east or west."
The UN agency for Palestinian refugees, UNRWA, said "thousands of people" broke into several of its warehouses and distribution centres in Gaza, grabbing basic survival items like wheat flour and hygiene supplies.
"This is a worrying sign that civil order is starting to break down," it said.
Outside a bakery in southern Gaza's Rafah, Etidal al-Masri was queueing but did not know if she would get bread.
Having been displaced from northern Gaza, Masri lamented that Gazans "must now queue for bread, toilets and even for sleep".
Communications were down for days after Israel cut internet lines ahead of the intensification of operations in the territory, although connectivity was gradually returning on Sunday.
Mirjana Spoljaric, president of the International Committee of the Red Cross, voiced shock at the suffering in Gaza and urged all sides to de-escalate.
"This is a catastrophic failing that the world must not tolerate," she said.
Pro-Palestinian rallies were held in Madrid, Athens and Casablanca on Sunday calling for a ceasefire.
A US government official, speaking on condition of anonymity, said 40 more aid trucks may enter Gaza on Sunday and that Israel was committed to allowing 100 to arrive daily.
'All areas are dangerous'
On Sunday Israel's military said it had struck hundreds of Hamas targets and increased its ground forces in Gaza.
The army said troops had "confronted" militants who emerged out of a tunnel in north Gaza, highlighting challenges in Hamas's vast underground network to Israel's ground operation.
In a late-night televised address on Saturday, Netanyahu announced a "second stage of the war" to "eradicate" Hamas, the Palestinian Islamist movement that has governed Gaza since 2007.
The "burden" lies with Israel to distinguish between militants and innocent civilians in Gaza, US National Security Advisor Jake Sullivan told CNN television.
Israeli military spokesman Daniel Hagari again urged Palestinian civilians to go south "to a safer area", but residents remained wary as air strikes continue.
Ibrahim Shandoughli, a 53-year-old from Jabaliya in northern Gaza, told AFP he and his family went nowhere.
"Where do you want us to evacuate to? All the areas are dangerous."
While Israel mourned its dead, sympathy has swelled for the families whose loved ones were abducted by Hamas and are at heightened risk as the war intensifies in Gaza.
Hamas has released four hostages but this week said "almost 50" had been killed by Israeli strikes, a claim that was impossible to verify.
"We demanded that no action be taken that endangers the fate of our family members," said Meirav Leshem Gonen, the mother of hostage Romi Gonen.
Hamas's armed wing said it was prepared to release the hostages if Israel freed the Palestinian prisoners it was holding.
Ifat Kalderon, whose relatives are believed held in Gaza, told AFP she supported the idea of a prisoner release in exchange for the hostages.
"Take them, we don't need them here," she said, referring to Palestinian detainees.
The ground operations have heightened fears that Israel's other enemies - the Iran-allied "axis of resistance" forces in Lebanon, Syria, Iraq and Yemen - enter the conflict.
Top ally the United States has warned Israel's enemies to stay out and strengthened its military presence in the region.
Skirmishes have intensified on the Israeli-Lebanese border with Iran-backed Hamas ally Hezbollah, raising fears of a new front.
Hezbollah, which reported one of its fighters was killed on Sunday, said it downed an Israeli drone, while Hamas's military wing in Lebanon announced it had launched rockets at Israel.
Iran's President Ebrahim Raisi warned on X, formerly Twitter, that Israel's "crimes have crossed the red lines, which may force everyone to take action".
Violence has also spiked in the occupied West Bank since the October 7 attacks, with more than 110 Palestinians killed, according to the territory's health ministry.