Heavy fighting raged Sunday in the Israel-Hamas war as UN chief Antonio Guterres called for a surge of aid into the besieged territory he said was stalked by "horror and starvation".

Talks have been held in Qatar towards a truce and hostage release deal but the heads of the CIA and Mossad have left Doha for consultations with their governments, an informed source told.

Air and artillery strikes again rained down on Gaza where Israel has vowed to launch its planned ground offensive against Hamas in the crowded far southern city of Rafah, despite rising global concern and objections from the United States.

The health ministry in the Hamas-run Gaza Strip said Sunday that another 84 people had been killed over the previous 24 hours, raising the total death toll in the territory during nearly six months of war to 32,226.

Palestinian children badly wounded in the latest bombardment were rescued from the rubble of collapsed buildings and rushed for urgent medical care to Al-Najjar hospital in Rafah.

Guterres, on a visit to Egypt, urged an end to the "non-stop nightmare" endured by Gaza's 2.4 million people since Hamas sparked the territory's worst ever war with its October 7 attack on Israel.

"Looking at Gaza, it almost appears that the four horsemen of war, famine, conquest and death are galloping across it," the United Nations secretary-general said.

"The whole world recognises that it's past time to silence the guns and ensure an immediate humanitarian ceasefire."

As UN and other aid agencies have warned of the threat of famine in Gaza, Guterres urged Israel to allow in more humanitarian aid via the Rafah border crossing where trucks were queued up.

Israel's military blasted back on social media, saying the UN should scale up its logistics and "stop blaming Israel for its own failures."
 
   - Hospital battles -

Combat has flared for almost a week in and around Gaza's biggest hospital complex, Gaza City's Al-Shifa, which has been a refuge for displaced people and where Israel says Palestinian Hamas have been hiding out.

The Hamas government media office said 190 people had been killed in the Al-Shifa operation, and 30 nearby buildings destroyed.

The army said its forces have killed more than 170 Hamas and detained about 480 "affiliated with the Hamas and Islamic Jihad terrorist organisations".

The Palestinian Red Crescent said Sunday that Israeli forces were also besieging two other medical centres, the Nasser and Al-Amal hospitals in southern Gaza's Khan Yunis.

The Red Crescent said messages broadcast from drones demanded that everyone in Al-Amal leave naked, while forces blocked the gates of the hospital with dirt barriers.

"All of our crews are currently under extreme danger and cannot move at all," the Red Crescent added.

Israel's military said it began an operation in the Al-Amal neighbourhood "in order to continue dismantling terrorist infrastructure and eliminating terrorist operatives".

The military said the operation began with air force strikes on about 40 targets, including military compounds and tunnels.

In Rafah city, local resident Hassan Zanoun looked sadly at the remains of his building, reduced to a jumble of broken concrete and rubble.

"My children and I were sleeping here," he said. "Suddenly everything was unleashed over our heads... strikes, screams.

He said he and his daughters "got out from under the rubble" but were injured, along with their neighbours.
 
   - 'Protecting civilians' -

Israel has faced ever greater global opposition to its military campaign as Palestinian civilian deaths have soared and its siege has brought widespread malnutrition and hunger.

Jordan's King Abdullah II stressed in a phone call with French President Emmanuel Macron the need for "an immediate and permanent ceasefire in Gaza and protecting innocent civilians", the palace said.

He also called for more aid to reach Gaza as his country's planes again airdropped relief supplies there with aircraft from the United States, Egypt, Germany and Singapore.

The Gaza war was sparked by the unprecedented Hamas attack on October 7 that resulted in about 1,160 deaths in Israel, mostly civilians, according to a tally based on official Israeli figures.

Israel has vowed to destroy the Hamas, who also seized about 250 hostages, of whom Israel believes around 130 remain in Gaza, including 33 presumed dead.

Relatives and supporters of the hostages, demanding greater efforts to bring them home, rallied Saturday outside the defence ministry in Tel Aviv, where some scuffled with police.
 
   - US-Israel tensions -

Tensions have grown between Israel and its top ally the United States, which provides billions of dollars in military aid to Israel but has called for greater efforts to alleviate Gaza's humanitarian crisis.

A major flashpoint is Israel's plan to push its ground invasion into Rafah city on the Egyptian border, where around 1.5 million Palestinians have sought refuge, mostly in overcrowded shelters.

Washington has made clear it would not support an Israeli attack on Rafah without a plan to protect civilians there.

Israeli Prime Minister Benjamin Netanyahu argued that "we have no way to defeat Hamas without getting into Rafah and eliminating the battalions that are left there".

Netanyahu said he had told Secretary of State Antony Blinken that "I hope to do that with the support of the United States, but if we need to, we will do it alone".

Israeli Defence Minister Yoav Gallant was to head to Washington Sunday to discuss the war with Pentagon chief Lloyd Austin and other senior US defence officials.

At the truce talks in Doha, a major sticking point has been Hamas's position that a temporary truce must lead to a permanent Israeli withdrawal from Gaza, a demand Israel has rejected.

CIA chief Bill Burns and his Israeli counterpart David Barnea departed Doha late Saturday, a source briefed on the talks said.

The latest negotiations had "focused on details and a ratio for the exchange of hostages and prisoners", the source said, adding that technical teams remained in Qatar.