Israeli troops have encircled Gaza City as the UN chief slams the offensive as "systematic destruction", with thousands of Palestinians unable or unwilling to flee.
Israel confirmed on Tuesday that it had begun its long-anticipated ground operation into Gaza City, where hundreds of thousands of displaced Palestinians remain.
The Israel Defense Forces (IDF) heavily bombarded the area, which had sustained increased air strikes for more than a week, mainly targeting high-rises.
There are about 600,000 Palestinians left in the city, with the IDF estimating 40 per cent of the population had left.
Hamas said about 350,000 left their homes in the eastern parts of the city, heading to displacement shelters in its central or western areas, while another 175,000 people had fled the city altogether, heading south.
"We don't have a place in the south, and we tried before to flee, and we fled 16 times but it was in vain, each time was more expensive than the one before," Iman Al-Ijlah, 23, told the ABC.
"We are not capable of fleeing, and currently we want to stay in Gaza, me and my family, and we can't leave."
United Nations secretary-general António Guterres has condemned the continuing assault, saying it is morally, politically and legally intolerable.
"What happened in Gaza today is horrendous. We are seeing massive destruction of neighbourhoods, now the systematic destruction of Gaza City," he said.
"We are seeing massive killing of civilians in a way that I do not remember in any conflict since I am secretary-general."
Mr Guterres said the Palestinian people were suffering a horrendous situation "with famine, with no access to any kind of health support and with continued displacement and the imminent risk of losing their lives at any moment".
"This is something we cannot forget. Independently of the names that are given, the truth is that this is something that is morally, politically and legally intolerable."
The IDF claims there are about 3,000 Hamas fighters left in the city, which it labels as the group's main stronghold, and "central hub of [its] military and governing power".
It accuses it of turning the city "into the largest human shield in history" and preventing civilians from leaving to go to the "humanitarian zone" in the south.
Hamas denies these allegations and accuses Israel of lying to justify the "systematic destruction" of the city.
Iman Al-Ijlah said the IDF was misleading people and that there was "no humanitarian area in the south".
"The danger will follow us wherever we go. Until now, there is no safe area. I could flee to Deir al-Balah, Nuseirat or Khan Younis, wherever, in the central area or the south, and then I will be bombed and die. So what did I benefit from fleeing?" she asked.
'Nothing left'
As the ground invasion was underway, Israeli Defence Minister Israel Katz posted on X that "Gaza is burning".
The IDF had been striking hundreds of buildings in the lead-up to Tuesday, with much of the cityscape already levelled.
"I lived next to the towers and tall buildings, and the military for 24 hours [a day] until this moment is bombing, the buildings, everything is bombarded, nothing is left from the city," Iman said.
The ABC has confirmed Israeli troops have reached at least two areas surrounding Gaza City
A social media video also shared by Israeli TV, geolocated and verified by the ABC and Reuters, showed IDF tanks close to the sea in Jabalia, north-west of Gaza City.
The exact date when the video was filmed could not be verified. However, based on recent satellite imagery, Reuters confirmed it was filmed after Friday, September 12.
ABC staff in Gaza have also confirmed the army is setting base in a school building on the outskirts of Gaza City, to the east.
[MAP]Palestinian local health authorities said an Israeli strike had hit a vehicle carrying displaced people fleeing south near the coastal road in Gaza City, which the IDF was telling people to use to evacuate.
The Ministry of Health had earlier warned there was "severe overcrowding in emergency departments in the remaining functioning hospitals in Gaza City".
It said medical teams were operating with depleted stocks of essential medicine supplies and a severe shortage of blood units.
The latest deaths take Tuesday's toll to at least 75, most of them in Gaza City.
Khaled Hamad from Beit Hanoun, who was also sheltering in the city, said the bombardment was escalating at night.
"During the day the sun is shining, at night the light we see is the flames of the missiles and shells," he said.
"Our children are terrified and the elderly are going through severe mental difficulties."
The beginning of the ground invasion coincided with a UN Commission of Inquiry finding that Israel was committing genocide in Gaza.
According to the report, "genocidal intent was the only reasonable inference" the commissioners could draw based on Israel's conduct.
More than 20 major aid groups working in Gaza have called on world leaders, who will be gathering in New York for the UN General Assembly next week, to intervene.
"Now, as the Israeli government has ordered the mass displacement of Gaza City – home to nearly 1 million people – we are on the precipice of an even deadlier period in Gaza’s story if action is not taken," the statement, signed by groups including Oxfam and Save The Children, said.
"Gaza has been deliberately made uninhabitable."
'Army has no mercy'
Israel's military had been for weeks instructing those in Gaza City to evacuate to the so-called humanitarian area in the South, warning it was considered a dangerous combat zone, and dropping leaflets telling them to use the main road.
Prime Minister Benjamin Netanyahu said Israel was "making efforts to open additional routes to enable a faster evacuation of the Gazan population".
Columns of Palestinians streamed towards the south and west in donkey carts, rickshaws, heavily laden vehicles or on foot.
Rafiq Abu Jarrad told the ABC he was trying to heed the warnings for his children's sake, but it was very difficult and costly, with a lack of cars to move south.
"I booked a place in Deir al-Balah, and I rented 100 square meters, for 5 shekels for a square meter, so it's 500 shekels a month just for a plot of land to put a tent and a bathroom," he said.
"I had to do it, because the army does not have mercy on anyone and I have experienced it this year, that when the Israelis order the population to leave, and they don't leave, the tanks and the aeroplanes and the ships bomb everywhere, without mercy, not for a child, not an old man and not a woman."
"My children are 90 per cent of the reason I want to flee, because I am afraid for them, I am not afraid about myself or my wife."
Political backlash
In launching the assault, Israel's government defied not only European leaders threatening sanctions, but even warnings from some of Israel's own military commanders that it could be a costly mistake.
US President Donald Trump sided with Israel, telling reporters at the White House that Hamas would have "hell to pay" if it used hostages as human shields during the assault.
Israeli Prime Minister Benjamin Netanyahu said Trump had invited him to the White House in two weeks, after both men had addressed an annual gathering of world leaders at the United Nations General Assembly.
In the latest expression of international alarm, a United Nations Commission of Inquiry concluded that Israel had committed genocide in Gaza. Israel called the assessment "scandalous" and "fake".
European Union foreign policy chief Kaja Kallas said on Tuesday that Israel's ground offensive in Gaza would worsen the situation in the enclave.
"Israel's ground offensive in Gaza will make an already desperate situation even worse," Ms Kallas wrote on social media platform X.
"It will mean more death, more destruction & more displacement," she said, noting that the European Commission would present measures on Wednesday to pressure the Israeli government to change course.
Hours before the escalation, US Secretary of State Marco Rubio said in Jerusalem that, while the United States wished for a diplomatic end to the war, "we have to be prepared for the possibility that's not going to happen".
In Brussels, a spokesperson for the EU executive said it would agree on Wednesday to impose new sanctions on Israel, including suspending certain trade provisions.
Mr Netanyahu told a press conference on Wednesday that if there was one lesson learned from the Gaza war, it was that Israel needed to create an "independent weapons industry" that could "withstand international constraints".
ABC/Reuters
