The Israeli military launched a ground offensive deeper into Gaza City on Tuesday with a stated goal of eradicating Hamas, according to Israeli officials.

Residents reported near-relentless shelling in the centre of the capital overnight as crowds fled towards the outskirts.

A senior IDF official told Axios that ground forces had entered Gaza City on Monday, with more to join them in the coming days as part of a ground offensive to occupy the metropolitan area.

Israeli Defence Minister Israel Katz said early Tuesday that Gaza City, the territory's main urban hub, was 'on fire'.

'We will not relent and we will not back down until the mission is accomplished,' Katz wrote on X, without specifying whether this was part of a formal new operation.

The Jerusalem Post also reported that a major offensive had begun, citing Palestinian reports that tanks were rolling into the heart of the city in 'levels of war not seen in northern Gaza in possibly two years'.

Overnight strikes in Gaza City killed at least 12 Palestinians, including two children, according to Shifa Hospital, which the received the bodies.

'It was a heavy night,' said Radwan Hayder, a Gaza City resident sheltering near the hospital.

It came hours after U.S. President Donald Trump issued a stark warning to Hamas, saying that if reports it was moving hostages above ground to be used as human shields were true, 'all bets are off'.

Smoke rises following Israeli airstrikes that hit and destroyed multiple buildings and high-rise towers in Gaza City, Gaza on September 14

Smoke rises from Gaza after an explosion, as seen from the Israeli side of the border, September 16, 2025

Israeli soldiers work on their tanks and armored personnel carriers (APC) at a staging area on the border with Gaza Strip, as seen from southern Israel, Tuesday, Sept. 16, 2025

An Armored Personnel Carrier manoeuvres along the Israeli side of the border, as destruction in Gaza is seen in the background, in Israel September 16, 2025

'I hope the Leaders of Hamas know what they're getting into if they do such a thing,' the US president wrote on social media.

'This is a human atrocity, the likes of which few people have ever seen before. Don't let this happen or, ALL 'BETS' ARE OFF. RELEASE ALL HOSTAGES NOW!'

Trump was responding to news reports citing the mother of a captured Israeli claiming that she had been told her son was 'alone above ground in Gaza City'.

Merav Gilboa-Dalal, the mother of Guy Gilboa-Dalal, is among many families of hostages calling for an end to the war after nearly two years, fearing for their safety.

'Today, I know that my son is a human shield. And to find out that your son is a human shield - that is rock bottom. We can't breathe, there's no air,' she told Army Radio.

Hamas in turn said Trump's comments show 'blatant bias in favor of Zionist propaganda' and that Netanyahu was destroying the chances of reaching a ceasefire agreement.

'Washington knows that Netanyahu is sabotaging the chances of any agreement, most recently by attempting to assassinate the negotiating delegation in Qatar while they were discussing Trump's final deal,' Hamas said.

Israel has intensified its strikes on Gaza City, in the north of the Palestinian enclave, in recent weeks, accused of targeting residential towers and schools.

Marco Rubio speaks to the press as he departs Tel Aviv for Qatar following an official visit, at Ben Gurion International Airport, near Lod, Israel, September 16, 2025

An Israeli military vehicles driving by the border fence with a view of destroyed buildings in the besieged Palestinian territory on September 16, 2025

Smoke rises and an illumination flare is seen from the border region as Israel's attacks on the Gaza Strip continue unabated in Israel, on September 15

Smoke rises following Israeli airstrikes that hit and destroyed multiple buildings and high-rise towers in Gaza City, Gaza on September 14

The Netanyahu government says the city is one of Hamas' last strongholds in Gaza.

But senior IDF figures including IDF Chief of Staff Lt.-Gen. Eyal Zamir had vocally criticised the plan but refused to resign.

Critically, many hundreds of thousands of civilians remain in the capital, unable or unwilling to leave their homes.

The Jerusalem Post said that the IDF had anticipated residents would flee the city before the military operation intensified.

By Monday, some 300,000 had left their homes, but an estimated 700,000 people remained, it said.

An offensive deeper into Gaza City has received backing from the Trump administration in Washington.

US Secretary of State Marco Rubio said during a brief visit to Israel on Monday that there is 'a very short window of time in which a deal can happen' to end to the war.

Rubio said a diplomatic solution in which Hamas demilitarises remained the US preference, although he added: 'Sometimes when you're dealing with a group of savages like Hamas, that's not possible, but we hope it can happen.'

Rubio traveled on to Qatar in a bid to bring them back into the fold as negotiators to the conflict, after Israel's strike on its capital last week froze diplomatic efforts.

Israel 'launches ground invasion into Gaza City'