Tensions surged as Hamas's chief accused Israel on Tuesday of sabotaging talks for a Gaza truce after it raided the devastated Palestinian territory's largest hospital for a second time.

Months of war have pushed hundreds of thousands of Palestinians in the besieged territory to the brink of famine, with US Secretary of State Antony Blinken saying everyone in Gaza was now in need of humanitarian aid.

A UN-backed assessment meanwhile said 300,000 people in the territory's north would face famine by May without a surge of aid.

UN rights chief Volker Turk said Israel was blocking aid and conducting the conflict in a way that "may amount to the use of starvation as a method of war".

Israeli troops on Tuesday were pressing an assault on Gaza's biggest hospital, which they allege is being used for military purposes, saying more than 50 fighters had been killed and around 300 suspects arrested and taken for questioning.

In response, Hamas's Qatar-based chief Ismail Haniyeh accused Israel of seeking to "sow chaos and perpetuate violence" and "sabotage ongoing negotiations in Doha".

"The actions of the Zionist occupation forces at Al-Shifa Medical Complex confirm their intent to obstruct the recovery of life in Gaza and dismantle essential aspects of human existence," Haniyeh said.

It came as negotiations on a ceasefire in Qatar had restarted, after weeks of talks failed to secure a truce for the Muslim holy month of Ramadan, which began last week.

Israel's spy chief David Barnea kicked off a new round of talks with Egyptian and Qatari mediators on Monday.

Qatar's foreign ministry spokesman Majed al-Ansari said he was "cautiously optimistic" but it was "too early to announce any successes".

Ansari said they were expecting a counter-proposal to be presented to Hamas after both sides rejected previous offers, adding that technical talks would continue.

- 'Screamed in fear' -

The bloodiest ever Gaza war broke out after an unprecedented attack by Hamas on October 7 resulted in about 1,160 deaths in Israel, mostly civilians, according to an AFP tally of Israeli official figures.

Militants also seized about 250 hostages, of whom Israel believes 130 remain in Gaza, including 33 who are presumed dead.

Israel has responded with a relentless offensive against Hamas that has killed at least 31,819 people, most of them women and children, according to Gaza's health ministry.

Blinken, who will travel to Saudi Arabia and Egypt this week to try to shore up support for the temporary truce and an increase in aid, highlighted that everyone in Gaza was now suffering "severe levels of acute food insecurity".

"That's the first time an entire population has been so classified," he said during a visit to the Philippines.

Underlining his point, AFPTV footage showed desperate crowds gathered at the Jabalia refugee camp to get a portion of carrot soup.

"We came to queue, but they threw us out," said Jabalia resident Musaab al-Masry, lamenting that there was not enough food for everyone.

Further south, a diplomatic storm continued to rumble around the city of Rafah, where hundreds of thousands have sought refuge from fighting elsewhere in the territory.

US President Joe Biden is putting pressure on Israeli Prime Minister Benjamin Netanyahu to pull back from a threatened full-scale ground operation.

But Netanyahu said he told Biden "we are determined to complete the elimination of these battalions in Rafah, and there is no way to do this without a ground incursion".

The city is already under bombardment, with AFPTV footage showing residents picking through debris of buildings on Tuesday after another night of strikes.

Torrential rains piled onto the misery overnight, with many displaced having nowhere to run but makeshift tents.

Oum Abdullah Alwan said her children "screamed in fear" because "we can't tell the difference between the sound of rain and the sound of shelling".

- Hospital raid -

For the past two months, much of the Israeli military effort has been focused on the south.

Officials declared in January that the Hamas command structure in northern Gaza had been dismantled.

But the assault on Al-Shifa threw the spotlight back on the north.

Israel has long accused militants of using hospitals as bases and troops previously raided Al-Shifa last November, sparking an international outcry.

Military spokesman Daniel Hagari said this week that Palestinian militants and commanders had since returned to Al-Shifa "and turned it into a command centre".

An army statement late Tuesday said "dozens of prominent terrorists" from Hamas and the Islamic Jihad were among those arrested in the operation.

Witnesses reported air strikes and tanks near the hospital compound, which is crowded with thousands of displaced civilians, as well as the sick and wounded.

Also on Tuesday, a Palestinian man was killed by Jewish settlers in the occupied West Bank, a local official said, with the Israeli army saying a soldier shot a suspect during a disturbance.

According to the health ministry in Ramallah, Israeli troops and settlers have killed at least 430 Palestinians in the West Bank since the Gaza war began.

Blinken due in Mideast

US Secretary of State Antony Blinken was due to return Wednesday to the Middle East in a new bid to secure a truce in the Israel-Hamas war.

Following a failed attempt to secure a ceasefire in the war in the Gaza Strip by the start of the Muslim holy month of Ramadan last week, a new round of negotiations hosted by key mediator Qatar has begun.

On the ground, however, there was no sign of letup in the war that has devastated much of the Gaza Strip and forced hundreds of thousands of Palestinians to seek refuge in the south of the besieged territory.

The bloodiest ever Gaza war broke out after an unprecedented attack by Hamas on October 7 resulted in about 1,160 deaths in Israel, mostly civilians, according to an AFP tally of Israeli official figures.

Militants also seized about 250 hostages, of whom Israel believes 130 remain in Gaza, including 33 who are presumed dead.

Israel has responded with a relentless offensive against Hamas that has killed at least 31,819 people, most of them women and children, according to Gaza's health ministry.

- 'Starvation as method of war' -

Nearly six months into the war, Israel's key backer the United States has repeatedly called on its ally to allow an increase in the flow of humanitarian aid into Gaza.

Secretary of State Blinken was due in regional powerhouse Saudi Arabia on Wednesday and in Egypt, which neighbours Gaza and has been involved in previous mediation efforts, on Thursday.

He had earlier this week said everyone in Gaza was now suffering "severe levels of acute food insecurity".

"That's the first time an entire population has been so classified," he said during a visit to the Philippines.

A UN-backed assessment meanwhile said 300,000 people in the territory's north would face famine by May without a surge of aid.

UN rights chief Volker Turk said Israel was blocking aid and conducting the conflict in a way that "may amount to the use of starvation as a method of war".

AFPTV footage from Gaza showed desperate crowds gathered at the Jabalia refugee camp to get a portion of carrot soup.

"We came to queue, but they threw us out," said Jabalia resident Musaab al-Masry, lamenting that there was not enough food for everyone.

Israel's spy chief David Barnea kicked off a new round of talks with Egyptian and Qatari mediators on Monday.

Qatar's foreign ministry spokesman Majed al-Ansari said he was "cautiously optimistic" but it was "too early to announce any successes".

Ansari said they were expecting a counter-proposal to be presented to Hamas after both sides rejected previous offers, adding that technical talks would continue.

Despite the resumption of talks, there was little indication of an imminent agreement.

Israeli troops on Tuesday were pressing an assault on Gaza's biggest hospital, which they allege Hamas uses for military purposes, saying more than 50 fighters had been killed and around 300 suspects arrested and taken for questioning.

Lashing out over the Israeli operation at the Al-Shifa complex, Hamas chief Ismail Haniyeh accused Israel of seeking to "sow chaos and perpetuate violence" and "sabotage ongoing negotiations in Doha".

Israel has long accused militants of using hospitals as bases and troops previously raided Al-Shifa last November, sparking an international outcry.

Military spokesman Daniel Hagari said this week that Palestinian militants and commanders had since returned to Al-Shifa "and turned it into a command centre".

An army statement late Tuesday said "dozens of prominent terrorists" from Hamas and the Islamic Jihad were among those arrested in the operation.

Witnesses reported air strikes and tanks near the hospital compound, which is crowded with thousands of displaced civilians, as well as the sick and wounded.