The Israeli army said its ground forces had operated in southern Gaza overnight, after deadly strikes hit an ambulance convoy and a school-turned-refugee shelter in the besieged Palestinian territory.

Israeli troops have encircled Gaza's largest city, trying to crush Hamas in retaliation for October 7 raids that Israeli officials say killed an estimated 1,400 people inside Israel, most of them civilians.

The health ministry in Gaza, run by Hamas, says more than 9,200 Gazans, mostly women and children, have been killed in the Israeli military campaign.

At the Osama bin Zaid Boys School north of Gaza City, AFP saw the aftermath of what Hamas authorities said was Israeli tank shelling that killed 20 people.

Ambulance teams rushed into the debris-littered building to aid the wounded and remove the dead.

Stunned onlookers wept and wandered the scene with their hands clasped on their heads in horror and disbelief.

A long row of washing still hung from windows on the building's first storey, evidence that the school had become a temporary home for some of the hundreds of thousands displaced by the war.

The Israeli army describes Gaza City as "the centre of the Hamas terror organisation" and says it is targeting Hamas militants, weapons stores, tunnel complexes, drone launching posts and command centres there.

Israeli ground forces launched overnight "a targeted raid" in southern Gaza, the military said Saturday, where it has struck before but rarely sent in troops.

The "IDF (Israeli army) armoured and engineering corps operated to map out buildings and neutralise explosive devices," it said.

"The troops encountered a terrorist cell exiting a tunnel shaft. In response, the troops fired shells toward the terrorists and killed them."

Israel says it has struck 12,000 targets across the Palestinian territory since October 7, one of the fiercest bombing campaigns in recent memory.

A key focus of his Blinken's Israel visit on Friday was to convince Prime Minister Benjamin Netanyahu to enact "humanitarian pauses", which the United States believes could help secure the release of roughly 240 hostages thought to be in Hamas captivity, and to allow aid to be distributed to Gaza's beleaguered population.

Netanyahu said later, however, that he would not agree to a "temporary truce" with Hamas until the Islamist group releases the hostages.

Ambulance hit

In Gaza City, an Israeli strike on Friday hit an ambulance convoy near the territory's largest hospital Al-Shifa, killing 15 people, according to the Palestinian Red Crescent and the Hamas-run health ministry.

Israel's military said it had targeted an ambulance used by a "Hamas terrorist cell" and had "neutralised" those inside.

"We emphasise that this area in Gaza is a war zone. Civilians are repeatedly called upon to evacuate southward for their own safety," the army said.

An AFP journalist saw multiple bodies beside the blood-splattered Palestinian Red Crescent vehicle.

A child was carried away and a dead horse lay nearby, still tethered to a cart.

The Red Crescent said a convoy of five vehicles had been destined for the Rafah border crossing with Egypt, when they were struck multiple times.

One vehicle had been transporting a 35-year-old woman with shrapnel wounds.

World Health Organization chief Tedros Adhanom Ghebreyesus said he was "utterly shocked" by the strike.

A senior White House official said Hamas had tried to use a US-brokered deal opening the Egyptian border crossing to get its cadres out.

Hamas provided a list of wounded Palestinians for evacuation with one-third of the names those of Hamas members and fighters, the official said.

"That was just unacceptable to Egypt, to us, to Israel," the official added.

Egypt's health ministry said just 17 wounded Palestinians were evacuated for treatment in Egyptian hospitals Friday instead of the 28 originally planned because of the "events" at Al-Shifa.

Shuttle diplomacy

Blinken began the day in Amman by holding talks with Prime Minister and Foreign Minister Mohammed bin Abdulrahman al-Thani of Qatar, a mediator in the conflict.

He is also scheduled to meet the foreign ministers of Jordan, Egypt, Saudi Arabia and the United Arab Emirates.

The talks come amid mounting Arab anger over the civilian death toll from war, and increasing fears that the conflict could spread.

The leader of Lebanon's powerful Iran-backed Hezbollah movement, Hassan Nasrallah, on Friday broke weeks of silence to warn Israel the possibility of "total war is realistic".

Israel's Netanyahu warned Hezbollah it would "pay an unimaginable price" for any misstep.

Pentagon spokesman Brigadier General Patrick Ryder said he did not think Hezbollah would escalate fighting, telling the BBC "a broader regional conflict has been deterred".

"Right now, we see this conflict as contained between Israel and Hamas," he said.

The United States has sent two aircraft carrier groups to the eastern Mediterranean.