Israel announced the start of its long-awaited ground operation into Gaza City on Tuesday, declaring "Gaza is burning".
An Israeli military official said the Israeli Defence Forces had begun the main stage of their ground operation into Gaza City, the main urban centre in the enclave, where Israel has ordered hundreds of thousands of residents to flee.
A United Nations probe, meanwhile, on Tuesday charged Israel with committing "genocide" in the Palestinian territory and accused Prime Minister Benjamin Netanyahu and other top officials of incitement.
The military gave few initial details but said its troops had begun "dismantling Hamas terrorist infrastructure in Gaza City". Residents should leave.
"Gaza is burning," Defence Minister Israel Katz posted on X. "The IDF strikes with an iron fist at the terrorist infrastructure and IDF soldiers are fighting bravely to create the conditions for the release of the hostages and the defeat of Hamas."
Residents said bombardment of the city had been ramped up dramatically over the past two days, with heavier explosions that destroyed dozens of homes, and naval boats joining tanks and planes in the bombardment of the coast.
"We have launched a significant operation in Gaza," Netanyahu said at the start of testimony in court in an ongoing corruption trial.
A group representing hostages' families said they were "terrified" for their loved ones after Netanyahu ordered the strikes.
"He is doing everything to ensure there is no deal and not to bring them back," they said in a statement.
Rubio offers US backing
US Secretary of State Marco Rubio, who visited on Monday, offered apparent backing for the Israeli government's decision to abandon ceasefire talks and use force to smash Hamas.
While the United States wished to see a diplomatic end to the war, "we have to be prepared for the possibility that's not going to happen", Rubio said. He endorsed the Israeli demand that Hamas surrender its weapons and free all remaining hostages at once, as the only way to end the war.
Gaza health officials reported at least 24 people killed, most of them in Gaza City, in the early hours of the assault.
Netanyahu ordered the military last month to capture Gaza City, which he describes as the last stronghold of the militant group that launched the October 2023 surprise attack on Israel that precipitated the war.
Some 650,000 Palestinians believed to remain in Gaza City
Much of Gaza City was already laid to waste in the early weeks of the war in 2023, but around 1 million Palestinians had returned there to homes among the ruins. Forcing them out means nearly the entire population of Gaza will now be confined to encampments along the coast further south in what Israel calls a humanitarian area.
Israeli forces had been operating on the outskirts of Gaza City for weeks, edging closer to the centre of the city. An Israeli security official briefing reporters on Monday said around 320,000 people were estimated to have left Gaza City so far, while some 650,000 are thought to remain.
It was not possible to verify the figures independently. Thousands of residents have been fleeing in caravans with their belongings.
Israel's political leaders say the offensive is part of a plan to dismantle Hamas as a political and armed organisation. Netanyahu has insisted the group must lay down its weapons and have no future role in Gaza.
The Israeli military has levelled buildings in Gaza City suburbs in recent weeks, including high-rise towers.
The United Nations and countries critical of Israel's tactics say they amount to forced mass displacement and that conditions in the crowded southern areas where residents are being sent are dire, with little food.
Some Israeli military commanders have also expressed concern about the operation, warning that it could endanger the remaining hostages captured by Hamas during the October 2023 attacks, and may be a "death trap" for troops.
Hostage families gathered outside Netanyahu's home in Jerusalem late on Monday as news of the intensified strikes in Gaza streamed in.
"Our loved ones in Gaza are being bombarded by the IDF under the orders of the Prime Minister. The Prime Minister has decided to send IDF soldiers to areas where our loved ones are located, who might be harmed and not return alive," said Anat Angrest, whose son Matan is among the 20 hostages believed to still be alive.
"He is doing everything to ensure there is no deal and not to bring them back."
Israel has bombarded Gaza since Hamas's October 7 attack in 2023, in which more than 1,200 people, including an estimated 30 children, were killed and over 200 hostages taken, according to the Israeli government.
More than 64,000 Palestinians have been killed in Israel's subsequent campaign against Hamas in Gaza, according to Palestinian health officials, and flattened much of the densely populated strip, which is home to more than two million people.
The October 7 attack was a significant escalation in the long-standing conflict between Israel and Hamas.
