Israel sent tanks, troops and armoured bulldozers into the Gaza Strip in a "targeted raid" overnight that destroyed multiple sites before withdrawing from the Hamas-run territory, the army said Thursday.
Black smoke billowed into the night sky after a blast in the grainy night-vision footage the military released hours after Prime Minister Benjamin Netanyahu declared preparations for a ground war were underway.
On the 20th day of Israel's deadliest Gaza war yet, that has already killed thousands, the army said its forces had hit "numerous terrorist cells, infrastructure and anti-tank missile launch posts".
The operation in northern Gaza came in "preparation for the next stages of combat", it said, adding that the soldiers had "returned to Israeli territory".
The black-and-white video showed a column of armoured vehicles moving near Gaza's border fence. Other footage appeared to show an air strike and buildings being struck with munitions, sending debris flying high into the air.
Just hours earlier, Netanyahu had delivered a nationally televised address to Israelis still grieving and furious after Hamas's bloody October 7 attacks, telling them "we are in the midst of a campaign for our existence".
The shock attack, the worst in the country's history, saw throngs of Hamas gunmen pour from Gaza into Israel, killing more than 1,400 people, mostly civilians, and kidnapping 224 more, according to official tallies.
Israel has retaliated with relentless strikes that Gaza's Hamas-run health ministry said has killed more than 6,500, also mainly civilians -- a toll expected to rise substantially if Israeli troops massed near Gaza move in.
That scenario has further heightened international alarm as shock is growing about the scale of human suffering inside the besieged territory where Israel has cut off most water, food, fuel and other basic supplies.
In southern Gaza, a bereaved Palestinian woman, Umm Omar al-Khaldi, recounted to AFP how she witnessed her neighbours being killed in an Israeli strike that reduced the house to rubble, with many feared buried beneath.
"We saw them getting bombarded -- the children got bombarded while their mother was hugging them," the woman said, desperately pleading for help from the outside world.
"Where are the Arabs, where is humanity?" she said. "Have mercy on us, have mercy on us."
- 'Nowhere is safe' -
The war's surging death toll is by far the highest since Israel unilaterally withdrew from the small coastal territory in 2005 -- a period that has seen four previous Gaza wars.
Entire neighbourhoods have been razed, surgeons are operating without anaesthetic on some of the wounded, and ice-cream trucks have become makeshift morgues.
In chaotic scenes, volunteer emergency crew and neighbours have clawed, sometimes with their bare hands, through broken concrete and sand to pull out civilian casualties.
All too often they recover only their corpses, which have piled up, wrapped in blood-stained white shrouds.
"Nowhere is safe in Gaza," said Lynne Hastings, UN humanitarian coordinator for the Palestinian territories.
US President Joe Biden, a strong supporter of Israel, has joined the calls for it to "protect innocent civilians" and to follow the "laws of war" as it pursues Hamas targets.
Leaders of the 27-member European Union were on Thursday debating whether to call for a "humanitarian pause" in the war to deliver desperately needed aid.
French President Emmanuel Macron, speaking in Cairo on Wednesday, warned that "a massive intervention that would put civilian lives at risk would be an error".
And Jordan's King Abdullah said anger at the suffering could "lead to an explosion" in the Middle East.
- 'Raining down hellfire' -
Netanyahu -- amid the growing calls to temper the ferocious bombing campaign -- said that Israel had been "raining down hellfire on Hamas" and killing "thousands of terrorists".
He said his war cabinet and the military would determine the timing of a "ground offensive" with the goal to "eliminate Hamas" and "bring our captives home".
But he stressed that "I will not detail when, how or how many" forces would take part.
Netanyahu also acknowledged for the first time that he would have to explain the security lapses exposed on October 7.
"The fault will be examined and everyone will have to give answers, including me," he said. "But all this will happen later."
Biden, also contemplating the future, stressed that "when this crisis is over, there has to be a vision of what comes next".
He reiterated that Washington supports a two-state solution with independent Israeli and Palestinian states.
"It means a concentrated effort for all the parties -- Israelis, Palestinians, regional partners, global leaders -- to put us on a path toward peace," said the US president.
For now though, the raging war has sparked fears of a regional conflagration if it draws in more of Israel's enemies such as Iran-backed Syria and Hezbollah in Lebanon.
There has also been a rise of attacks on Israel's top ally the United States, which has a vast network of military bases across the Middle East.
About 2,500 American troops are stationed in Iraq and some 900 in Syria to help fight remnants of the Islamic State jihadist group.
The Pentagon said there were 10 attacks on US and allied forces in Iraq and three in Syria between October 17 and 24, involving a "mix of one-way attack drones and rockets."
By Jonah Mandel With Mai Yaghi In The Gaza Strip