The country’s defence minister said “the ground shook in Gaza” and that the war against the territory’s Hamas rulers has entered a new stage.

The bombardment, described by Gaza residents as the most intense of the war, also knocked out most communications.

This largely cut off the besieged enclave’s 2.3 million people from the world while enabling the Israeli military to control the narrative in a new stage of fighting.

The underground sites are a key target in Israel’s campaign to crush the territory’s ruling group after its bloody incursion in Israel three weeks ago.

“We moved to the next stage in the war,” defence minister Yoav Gallant said in remarks broadcast on Saturday. “Last evening, the ground shook in Gaza. We attacked above ground and underground. … The instructions to the forces are clear. The campaign will continue until further notice.”

His comments signalled the gradual ramping-up toward what is expected to evolve into an all-out ground offensive in northern Gaza.

Early in the war, Israel had already amassed hundreds of thousands of troops along the border. Until now, troops had conducted brief nightly ground incursions before returning to Israel.

The Palestinian death toll in Gaza on Saturday rose to just over 7,700 people since October 7, with 377 deaths reported since late Friday, according to the territory’s health ministry.

A majority of those killed have been women and minors, the ministry said.

Ministry spokesman Ashraf al-Qidra told reporters the disruption of communications has “totally paralysed” the health network.

Residents had no way of calling ambulances and emergency teams were chasing the sounds of artillery barrages and airstrikes to search for people in need.

Some civilians were using their bare hands to pull injured people from the rubble and loading them into personal cars or donkey carts to rush them to the hospital.

Other residents travelled by foot or car to check on their relatives and friends.

Israel says its strikes target Hamas fighters and infrastructure, and that the militants operate from among civilians, putting them in danger.

Across Gaza, terrified civilians were huddling in homes and shelters with food and water supplies running out. Electricity was knocked out by Israel in the early stages of the war.

More than 1.4 million people have fled their homes, nearly half crowding into UN schools and shelters.

Aid workers say the trickle of aid Israel has allowed to enter from Egypt in the past week is a tiny fraction of what is needed.

Gaza hospitals have been scrounging for fuel to run emergency generators that power incubators and other life-saving equipment.

The intensified air and ground campaign also raised new concerns about dozens of hostages dragged into Gaza on October 7th.

On Saturday, hundreds of relatives of hostages gathered in a square in downtown Tel Aviv, demanding to meet Israeli prime minister Benjamin Netanyahu and defence minister Mr Gallant. Some in the group demanded that Israel push for the release of all hostages before proceeding with the campaign against Hamas.  Mr Gallant later said he would meet the families on Sunday.

In Cairo, Egyptian president Abdel Fattah el-Sissi said his government was working to de-escalate the conflict through its talks with the warring parties to release prisoners and hostages.

The Israeli military said on Saturday it had killed the head of Hamas’ aerial wing, who had helped plan the October 7th attack by the Islamist group on Israel’s southern towns.

The Israeli Defence Forces said its fighter jets struck Asem Abu Rakaba, head of the Hamas Aerial Array, who was responsible for Hamas’ UAVs, drones, para-gliders, aerial detection and aerial defence.

“He took part in planning the massacre in the communities surrounding the Gaza Strip on October 7th. He directed the terrorists who infiltrated Israel on para-gliders and was responsible for the drone attacks on IDF posts,” the IDF said.

On Friday, the United Nations General Assembly overwhelmingly backed a resolution drafted by Arab states calling for an immediate humanitarian truce and demanded aid access to Gaza and protection of civilians.

While not binding, the resolution carries political weight, reflecting the global mood. It passed to a round of applause with 121 votes in favour, while 44 abstained and 14 – including Israel and the United States – voted no.

In New York late on Friday, hundreds of protesters demanding a ceasefire in the conflict forced officials to close Grand Central Terminal, one of the city’s major transit hubs, the Metropolitan Transportation Authority said.  The demonstration was organised by a group called Jewish Voice for Peace.

Mr Kirby would not comment on the expanded ground operation. But he said Washington supported Israel’s right to defend itself and added: “We’re not drawing red lines for Israel.”

He said that if getting more than 200 hostages abducted by Hamas out of Gaza required a localised temporary pause, the US supported that.

US defence secretary Lloyd Austin, in a call with Israeli defence minister Yoav Gallant, “underscored the importance of protecting civilians” during operations in Gaza, the Pentagon said on Friday.

Mark Regev, an adviser to Mr Netanyahu, told MSNBC that Israel was starting its payback against Hamas and “Gaza will feel our wrath tonight”.

“They will continue to be on the receiving end of our military blows until we have dismantled their military machine and dissolve their political structure in Gaza,” he told Fox News. “When this is over, Gaza will be very different.”

Russian foreign minister Sergei Lavrov has said on Saturday that Israel’s bombardment of Gaza runs counter to international law and risks creating a catastrophe that could last decades.

Mr Lavrov made the comments, some of Moscow’s most critical of Israel yet, in an interview with the Belarusian state news agency Belta, which released them on Saturday.

“While we condemn terrorism, we categorically disagree that you can respond to terrorism by violating the norms of international humanitarian law, including indiscriminately using force against targets where civilians are known to be present, including hostages that have been taken,” said Mr Lavrov.

It was impossible, he added, to destroy Hamas – as Israel has vowed to do – without destroying Gaza along with most of its civilian population.

“If Gaza is destroyed and two million inhabitants are expelled, as some politicians in Israel and abroad propose, this will create a catastrophe for many decades, if not centuries,” warned Mr Lavrov. “It is necessary to stop, and to announce humanitarian programmes to save the population under blockade.”

Concerns about a risk of a wider Middle East conflict have risen in recent days with the US dispatching more military assets to the region as Israel pummeled targets in Gaza and Hamas supporters in Lebanon and Syria.

Much of the infrastructure of Gaza, which has been living under blockade by Israel and Egypt since 2007, has been shattered by Israeli bombing.

Palestinians said they received renewed Israeli military warnings to move from Gaza’s north to the south to avoid the deadliest theatre of the war. Making the journey south remains highly risky amid air strikes and southern areas have also been bombed, Gaza residents said.

Many families have refused to leave, fearing a repeat of the experience of previous wars with Israel when Palestinians who left their homes and land were never able to return. – AP/Reuters