(AFP) - Israel bombed Gaza on Thursday in its war against Hamas militants 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. It began a relentless bombardment and ground invasion that has left swathes of Gaza in ruins. According to the Hamas-run health ministry's latest toll, 18,608 people, mostly women and children, have been killed.

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

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" as a result of ongoing Israeli "aggression" 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 on Wednesday. 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, nothing less than that", and Foreign Minister Eli Cohen said the war would continue "with or without international support".

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.

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".

A poll by the Palestinian Centre for Policy and Survey Research showed Haniyeh had the support of 78 percent of people in the Palestinian territories, compared with 58 percent before the war.

- 'Darkest chapter' -

CNN reported, citing US intelligence, that nearly half of the air-to-ground munitions used by Israel in Gaza since October 7 have been unguided, which can pose a greater threat to civilians.

International pressure is mounting on Israel to better protect non-combatants. This week, the UN General Assembly overwhelmingly supported a non-binding resolution for a ceasefire.

While Washington voted against, the resolution was supported by allies Australia, Canada and New Zealand. In a rare joint statement, the three countries said they were "alarmed at the diminishing safe space for civilians in Gaza".

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

The head of the United Nations 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".

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

"Where do we migrate to? Our dignity is gone. Where do women relieve themselves? There are no bathrooms," said Bilal al-Qassas, 41, who fled to the southern city of Rafah which has become a vast camp.

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

- Disease spreading -

Samar Mohammed, a 38-year-old teacher, fled with her family to a friend's home in Rafah. They have been told they could pay thousands of dollars in bribes to get out, "but haven't found anyone we trust not to steal from us", she said.

The UN warned the spread of diseases -- including meningitis, jaundice and upper respiratory tract infections -- had intensified.

Fewer than one-third of Gaza's hospital are partly functioning, the UN says, and Hamas authorities said vaccines for children have run out, with "catastrophic health repercussions".

The World Health Organization called for the "protection of all people inside" Kamal Adwan hospital in north Gaza. The Hamas-controlled health ministry said Israeli forces had opened fire on wards of the facility.

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

Major Keren Hajioff, an Israeli military spokesperson, on Thursday said troops had found "weapons depots and tunnels in multiple schools", as well as a rocket-propelled grenade training facility "inside a mosque in Jabalia."

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 began raiding Jenin, where the Israeli military says it has seized weapons, dismantled explosives laboratories, tunnel shafts and other military facilities.

The Israel-Hamas 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 last month.

Other captives have been found dead. Tanzania on Thursday confirmed the death of one of its nationals, a student, killed after his capture on October 7.

Smoke rose above the hills over southern Lebanon on Thursday after Israeli bombardment. Lebanese Hezbollah militants and Israeli forces have been engaged in regular exchanges of fire since the Israel-Hamas war began.

© Agence France-Presse