Israel said Tuesday 24 soldiers were killed in the biggest single-day losses since the start of its ground war in Gaza amid growing pressure on the government to find a way to end the conflict.

The heavy clashes came as a White House official was due in the region for talks aimed at securing more hostage releases, and as US media reported a new Israeli proposal for a deal that would involve a two-month pause in fighting.

Twenty-four soldiers were killed on Monday, with the army saying 21 of them were reservists slain when rocket-propelled grenade fire hit a tank and two buildings they were trying to blow up.

Prime Minister Benjamin Netanyahu said an investigation was launched into the "disaster" and that Israel "must learn the necessary lessons". Defence Minister Yoav Gallant said the "deaths of 24 of our fighters, our best sons... is a heavy blow".

More than 200 people attended the funeral of one of the reservists, Hadar Kapeluk, whose coffin was draped with an Israeli flag, at Mount Herzl military cemetery in Jerusalem.

An analyst said the mounting toll of soldiers killed -- now 221 -- since Israel launched its ground offensive in Gaza would heap pressure on the government.

"Everybody is mourning the soldiers this morning and I think people will demand clear answers about the purpose and the goal of this operation in Gaza," said Israela Oron of the Ben-Gurion University of the Negev.

On the ground, fighting raged in Khan Yunis, the biggest city in southern Gaza, which the army said it had "encircled".

Witnesses said powerful explosions rocked Khan Yunis, as well as Deir al-Balah in north Gaza and Rafah in the south.

Medical charity Doctors Without Borders (MSF) said its staff at Khan Yunis's Nasser Hospital felt the "ground shaking".

The Palestinian Red Crescent said Israeli forces had hit its headquarters in Khan Yunis "resulting in injuries among internally displaced individuals who sought safety on our premises".

- 'Looming threat of famine' -

UN agencies and aid groups have sounded the alarm about the growing threat of disease and famine in Gaza, where 1.7 million people are estimated to have been uprooted.

"The situation in Gaza is of course slipping every day into a much more catastrophic situation," with "a looming threat of famine", said Abeer Etefa, the World Food Programme's senior spokeswoman for the Middle East.

Abu Iyad, his belongings piled on a donkey-drawn cart, said he was moving for the seventh time, fleeing Khan Yunis for Rafah on the Egyptian border, where hundreds of thousands of displaced Palestinians have sought shelter, many in makeshift tents.

"I'm heading to the unknown," he told AFP. "They told us to go to Rafah -- where to go in Rafah? Is there any space left?"

The Gaza war broke out with Hamas's unprecedented October 7 attacks, which resulted in the deaths of about 1,140 people in Israel, mostly civilians, according to an AFP tally based on Israeli official figures.

In response, Israel has carried out a relentless offensive that has killed at least 25,490 people in Gaza, mostly women and children, according to the health ministry in the Hamas-run territory.

The Hamas attack also saw about 250 hostages seized, and Israel says around 132 remain in Gaza. That number includes the bodies of at least 28 dead hostages, according to an AFP tally based on Israeli figures.

A week-long truce in November saw 105 hostages released, the Israelis among them in exchange for Palestinian prisoners held in Israeli jails.

Relatives of those still held captive stormed a parliamentary committee meeting on Monday demanding urgent action.

"You sit here while our children are dying over there," yelled Gilad Korngold, father of hostage Tal Shoham, an AFP correspondent reported.

- Two-state solution -

US news outlet Axios reported on Monday night that Israel had proposed to Hamas, via Qatari and Egyptian mediators, a new deal to free all the hostages.

The report, citing unnamed Israeli officials, said the proposed deal would be carried out in multiple stages, and would also involve the release of an undetermined number of Palestinian prisoners.

The plan was expected to take about two months to complete.

The proposal does not include promises to end the war, but it would involve Israeli troops reducing their presence in major cities in Gaza and gradually allowing residents to return to the territory's devastated north, Axios said.

News of the proposal comes as US media said the White House's coordinator for the Middle East, Brett McGurk, was expected in Egypt and Qatar for meetings aimed at securing a new hostage exchange deal.

State Department spokesman Vedant Patel, however, said Washington still believed "a two-state solution, a creation of a Palestinian state, is the only path that gets us out of this endless cycle of violence".

Netanyahu has steadfastly rejected calls for the creation of a Palestinian state, saying Israel must maintain "security control over all the territory west of the Jordan" River, an area that includes all of the Palestinian territories.

- US, UK hit Yemen's Huthis -

EU foreign ministers pressed Israel to change its mind at meetings in Brussels on Monday with the top diplomats from the two warring parties and key Arab states.

"The two-state solution is the only solution, and even those who don't want to know about it have not yet come up with any other alternative," said German Foreign Minister Annalena Baerbock.

At the gathering, Israeli Foreign Minister Israel Katz ignored questions from journalists over a future two-state solution and said his country was focused on returning the hostages and ensuring its security.

Jordanian Foreign Minister Ayman Safadi, who was also in attendance, said Israel's rejection of "the two-state solution is dooming the future of the region to more conflicts".

The Gaza war spurred fears of a wider escalation, with a surge in violence involving Iran-backed Hamas allies across the region.

Lebanon's Shiite movement Hezbollah said Tuesday it struck the Israeli air control base of Meron for a second time in recent weeks, in response to Israeli "assassinations" and attacks on civilians.

The United States and Britain launched a new wave of air strikes against Yemen's Iran-backed Huthi rebels on Tuesday over their attacks on Red Sea shipping.

In response, the Huthis warned that "these attacks will not go unanswered and unpunished".