GAZA STRIP, Palestinian Territories, Dec 14, 2023 (BSS/AFP) - Israel bombarded Gaza on Thursday in its war against Hamas as a top White House adviser travelled to Jerusalem with a rift growing over civilian casualties.

The war, now in its third month, began after the Palestinian group's unprecedented October 7 attacks on Israel that Israeli officials say killed about 1,200 people, mostly civilians.

In response, Israel vowed to destroy Hamas and launched a relentless bombardment and ground invasion that has left swathes of Gaza in ruins. The health ministry in the Hamas-run territory said 18,787 people have been killed, mostly women and children.

Israeli air strikes across Gaza overnight killed at least 67 more, the health ministry said earlier.

In Gaza's southern city of Khan Yunis, smoke rose from a grey landscape of rubble which people combed with shovels and their bare hands after a strike. One man sat on the broken concrete, wiping his eyes.

"Around four people are still stuck under the rubble" after an airplane hit the building "without a warning", said Hassan Bayyout, 70.

In the Israeli-occupied West Bank, where violence since October 7 has surged to levels unseen in nearly two decades, the Palestinian health ministry said "a young man died from his wounds" received during an Israeli raid in Jenin, a militant stronghold.

US President Joe Biden, whose government has provided Israel with billions of dollars in military aid, delivered his sharpest rebuke of the war this week. He said Israel's "indiscriminate bombing" of Gaza was eroding international support.

But Israel's Prime Minister Benjamin Netanyahu vowed to carry on "until victory" and Foreign Minister Eli Cohen said the war would continue "with or without international support".

- 'Darkest chapter' -

On Thursday, Biden's National Security Advisor Jake Sullivan was due in Jerusalem for talks with Netanyahu and his war cabinet, a sign of the US pressure.

Sullivan told a Wall Street Journal event ahead of his trip that he would discuss a timetable to end the war and urge Israeli leaders "to move to a different phase from the kind of high-intensity operations that we see today".

Netanyahu has said there is also "disagreement" with Washington over how Gaza would be governed after the war.

Israel rejects the two-state solution Washington is insisting upon.

Qatar-based Hamas chief Ismail Haniyeh said on Wednesday that "any arrangement in Gaza or in the Palestinian cause without Hamas or the resistance factions is a delusion".

This week, the UN General Assembly overwhelmingly supported a non-binding resolution for a ceasefire, which Washington voted against.

The United Nations estimates 1.9 million out of Gaza's 2.4 million people have been displaced.

The head of the UN agency for Palestinian refugees, Philippe Lazzarini, said on Wednesday that Gazans were "facing the darkest chapter of their history".

He said they are "now crammed into less than one-third" of the territory, and hinted there could be an exodus to Egypt, "especially when the border is so close".

- Hospital a focus -

Cold wintery rain has lashed the makeshift tents where the homeless struggle to survive without sufficient food, drinking water, medicines or cooking fuel, with diseases spreading.

After a strike in Rafah, where many Palestinians have fled, the faces of relatives were contorted in grief after they identified the body of a child, Muhannad Ashour, at Najjar hospital.

Despite the needs, aid distribution has largely stopped in most of Gaza, except on a limited basis in the Rafah area, the UN says.

COGAT, the Israeli defence ministry body responsible for Palestinian civilian affairs, said the military "is enabling tactical pauses for humanitarian purposes". One was taking place Thursday for four hours in a Rafah neighbourhood to allow civilians to restock supplies such as food and water, it said.

Fewer than one-third of Gaza's hospitals are partly functioning, the UN says, and the World Health Organization expressed its concern about an Israeli raid on Kamal Adwan hospital in north Gaza.

The UN humanitarian agency OCHA said Wednesday that the hospital director and about 70 other medical staff "remain detained in an unknown location outside of the hospital".

It said Israeli forces had released five doctors and female staff but there were reports of "ill-treatment" of those who had been held.

The Hamas-controlled health ministry said Israeli forces had "fired at patient rooms". AFP was unable to confirm the situation independently.

On Thursday the army said that, during military activity in the hospital area, "over 70 terrorist operatives came out of the hospital with weapons in hand".

It said troops killed "a number" of militants during fighting in the area.

Israel has repeatedly accused Hamas of using hospitals, schools, mosques and vast tunnel systems beneath them as military bases -- charges it denies.

- Cross-border fire -

Israeli tank fire on Thursday shelled Gaza from the border area in southern Israel.

Militants have continued to fire rockets from Gaza towards Israeli territory.

The Palestinian health ministry said 10 people have been killed since Tuesday when Israeli forces in the West Bank began raiding Jenin, where the military says it has seized weapons, dismantled explosives laboratories, tunnel shafts and other military facilities.

The war has led to increased popular support for Hamas in the West Bank, which Israel has occupied since 1967.

In Israel, the army is coming under growing pressure to limit troop deaths -- it says 116 have been killed in Gaza -- and secure the release of remaining hostages.

Israeli authorities say 118 hostages are still believed to be alive in Gaza after their capture by militants on October 7. Some were released during an exchange for Palestinian prisoners during a week-long truce that ended on December 1.

The Israeli military said fighter jets on Thursday struck infrastructure and compounds of Hezbollah militants in Lebanon, after a munition was launched from Lebanon towards northern Israel.

Israeli forces and Hezbollah, a Hamas ally, have engaged in regular exchanges of fire since the Israel-Hamas war began.