Heavy fighting raged in central and southern Gaza on Wednesday as fears mounted of a regional escalation following a strike in Beirut that killed one of the top Hamas leaders.

Israel has refused to comment on reports it carried out the killing Saleh Arouri, the most senior Hamas member slain since the war in Gaza erupted nearly three months ago.

But on Wednesday, the chief of Israel's Mossad intelligence service vowed that the agency would hunt down every Hamas member involved in the Oct. 7 attack on Israel, no matter where they are.

The comments by David Barnea appeared to be the strongest indication yet it was behind Tuesday's blast. He made a comparison to the aftermath of 1972 Munich Massacre, when Mossad agents tracked down and killed a string of Palestinian militants involved in abducting and killing Israeli athletes at that year's Olympic games.

Hamas' Oct. 7 attack from Gaza into southern Israel killed around 1,200 people, and some 240 others were taken hostage. Israel's air, ground and sea assault in Gaza has killed more than 22,100 people, two-thirds of them women and children, according to the Health Ministry in the Hamas-ruled territory. The count does not differentiate between civilians and combatants.

Israel's campaign has driven some 85 per cent of Gaza's population from their homes, forcing hundreds of thousands of people into overcrowded shelters or teeming tent camps in Israeli-designated safe areas that the military has nevertheless bombed. A quarter of Gaza's population face starvation, according to the United Nations, as Israeli restrictions and heavy fighting hinder aid delivery.

Here's what's happening in the war:

UN UNABLE TO DELIVER AID TO NORTHERN GAZA

UNITED NATIONS --The United Nations and its humanitarian partners have been unable to deliver urgently needed aid to northern Gaza for three days due to conflict and delays and denial of access.

UN associate spokesperson Florencia Soto Nino told reporters Wednesday that the halt to deliveries north of Wadi Gaza included "medicines that would have provided vital support to more than 100,000 people for 30 days, as well as eight trucks of food for people who currently face catastrophic and life-threatening food insecurity."

Elsewhere, she said, UN officials from the humanitarian office and World Health Organization on Tuesday witnessed extensive damage at the Al Amal hospital in Khan Younis, which was reportedly struck, killing five people, including a five-day-old baby.

Soto Nino said WHO officials reported that many of the 14,000 civilians sheltering at the hospital have now left and those remaining are terrified and planning to relocate.

The UN humanitarian office has warned that "Gaza is a public health disaster in the making," and recent mass displacement across southern Gaza is fuelling disease outbreaks, she said.

Since Hamas' Oct. 7 surprise attacks, more than 400,000 cases of infectious diseases have been reported, Soto Nino said, including some 180,000 people with upper respiratory infections and over 136,000 cases of diarrhea -- half among children under 5.

ISRAEL SAYS IT HAS DESTROYED TUNNELS UNDER GAZA HOSPITAL

JERUSALEM -- Israel's military says it has destroyed tunnels laid out beneath Gaza's largest hospital, which forces raided late last year, prompting an international outcry .

The military says the operation to demolish the tunnels has not caused harm to the hospital itself. It said the tunnels are 250 meters (270 yards) long.

Video released by the military showed several explosions going off between buildings. The Associated Press could not independently verify the video.

Israel raided the hospital in November, saying Hamas uses it as a command and control centre, without providing evidence to directly prove that claim. Israel has discovered what it says is an underground bunker accessible by a narrow tunnel and videos appearing to show Hamas militants dragging hostages through the hospital's hallways.

The military's announcement Wednesday came after the U.S. said it was "confident" that Palestinian militant groups used the hospital to hold "at least a few" hostages seized during their bloody Oct. 7 attack and to house command infrastructure. Critics decried Israel's raid as dangerous for patients and an assault on Gaza's struggling health care system.

HEZBOLLAH LEADER PROMISES REVENGE FOR KILLING OF HAMAS OFFICIAL

Hezbollah leader Hassan Nasrallah promised revenge, repeating his group's statement that "this dangerous crime" of Arouri's killing will not go "without response and without punishment." But in a speech Wednesday, he left the audience guessing as to when and in what form.

Nasrallah said Hezbollah had so far been careful in its strategic calculus in the conflict, balancing "the need to support Gaza and to take into account Lebanese national interests." But if the Israelis launch a war on Lebanon, the group is ready for a "fight without limits."

"They will regret it," he said. "It will be very, very, very costly."

Nasrallah praised Arouri as well as Hamas' Oct. 7, attack, saying it "brought light back onto the Palestinian cause after it was nearly forgotten." He said Israel has so far failed in all its objectives in the Gaza war and was suffering damage to its international reputation.

ISRAEL SAYS HOSTAGE WAS KILLED IN FAILED RESCUE ATTEMPT IN GAZA

The Israeli military says a hostage taken captive by Hamas was killed in a failed rescue attempt in Gaza.

The hostage, 25-year-old Sahar Baruch, had been previously reported to have been killed, but Israel initially blamed Hamas, while Hamas said Israeli forces killed him in a raid.

The military said Wednesday it was not possible to determine whether Baruch died from Israeli fire or from Hamas in the rescue mission, which took place in early December.

The announcement about Baruch comes weeks after Israel said its forces accidentally killed three hostages in the Gaza Strip. Some relatives of hostages have said the protracted fighting puts the remaining captives at risk.

Following a hostage release deal in late November, some 129 hostages remain, although about 20 are said to have died in captivity.

UN SAYS 'NO ONE' SHOULD BE CALLING FOR MASS DISPLACEMENT

UNITED NATIONS -- The United Nations is implicitly criticizing Israel's far-right finance minister for his calls encouraging Palestinians in Gaza to leave the territory, reiterating the 193-member world body's strong opposition to forced displacement.

UN associate spokesperson Florencia Soto Nino told reporters Wednesday that "no one should be advocating for mass displacement of Palestinians out of Gaza."

She was responding to a post on X, formerly Twitter on Wednesday, by Israel's Finance Minister Bezalel Smotrich, who wrote that 70 per cent of Israelis support "voluntary migration" for Palestinians from Gaza to other countries.

Smotrich's initial call encouraging Palestinians to leave Gaza was met with an international outcry including from Israel's closest ally the United States, its top European ally Germany, and neighbouring Egypt.

Soto Nino stressed that Palestinian civilians should be safe in Gaza.

"Every person has the right to be protected from forced displacement from their home or residence, and so far 85 per cent of this population has been internally displaced and is living in pretty dire conditions," she said. "They have the right to return to their homes."

Here's what's happening in the war:

HEARINGS SCHEDULED FOR SOUTH AFRICA'S GENOCIDE CASE AGAINST ISRAEL

THE HAGUE, Netherlands -- The United Nations' top court has scheduled two days of preliminary hearings into a case filed by South Africa alleging that the Israeli military campaign targeting Hamas in Gaza meets the threshold of genocide under international law.

South Africa has asked the International Court of Justice to order Israel to halt its attacks in Gaza.

Israel strongly refutes the genocide allegation. An official in the Israeli prime minister's office, Eylon Levy, on Tuesday said Israel will "appear before the International Court of Justice at the Hague to dispel South Africa's absurd blood libel."

The court announced Wednesday that it will hold hearings on Jan. 11 and 12 into South Africa's urgent request for interim orders including that Israel halt its military campaign in Gaza.

If granted, such interim orders, known as provisional measures, would remain in place while the complex genocide case is heard by the court, a process that could take years.

The court's judges will likely issue a decision on the request for provisional measures within days or weeks.

ISRAELI MINISTER DOUBLES DOWN ON GAZA RESETTLEMENT

JERUSALEM -- Israel's far-right finance minister is doubling down on his calls to encourage Palestinians in Gaza to leave the territory despite an international outcry, including from the United States.

In a post on X, formerly Twitter, on Wednesday, Bezalel Smotrich wrote that 70 per cent of Israelis support "voluntary migration" for Palestinians from Gaza to other countries, saying that Israel couldn't allow itself to live so close to a "hotbed of hate." He did not say where the figure came from.

Smotrich, a champion of West Bank settlements, drew criticism from the U.S., Egypt, Germany and France after he made similar comments earlier this week while calling on Israel to reestablish settlements in the Gaza Strip. The State Department said his comments were "inflammatory and irresponsible."

Talk of mass displacement brings up difficult memories for Palestinians, some 700,000 of whom fled or were forced to flee during the war leading to Israel's creation in 1948.

Smotrich is a key partner in Prime Minister Benjamin Netanyahu's government, Israel's most nationalist and conservative. He has largely been sidelined by a War Cabinet that does not include him.

South Africa has cited statements by some Israeli officials as part of its argument at the International Court of Justice that Israel is committing genocide in Gaza.

GERMANY JOINS CRITICISM OF ISRAELI MINISTERS' RESETTLEMENT COMMENTS

BERLIN -- Germany has joined in strong criticism of two Israeli ministers' calls for Palestinians to be resettled outside Gaza.

Foreign Ministry spokesperson Sebastian Fischer said Wednesday that Berlin, a close ally of Israel, rejects the comments by Ministers Bezalel Smotrich and Itamar Ben Gvir "in the strongest terms" and that "they are neither useful nor helpful."

He underlined the position of Germany and its Group of Seven allies that "there must be no expulsion of Palestinians from Gaza, there must be no territorial reduction of the Gaza Strip."

He added that "from our point of view, a two-state solution remains the only sustainable model for Israelis and Palestinians to live together peacefully."

MACRON WARNS ISRAEL AGAINST FORCED DISPLACEMENT IN GAZA

PARIS -- French President Emmanuel Macron has warned Israel against contemplating a forced displacement of Gaza residents.

In a phone call on Tuesday with Benny Gantz, a member of Israel's War Cabinet, Macron "argued that statements relating to the forced displacement of Gazans were unacceptable and contradicted the two-state solution which constitutes the only viable solution for a return to peace and security for all," the president's office said in an overnight readout of the phone call.

Macron also warned against the risk of spreading conflict, saying it is "essential to avoid any escalatory attitude, particularly in Lebanon," the statement said. "France will continue to pass these messages to all actors involved directly or indirectly in the area," it added.

U.S. SLAMS 'IRRESPONSIBLE' COMMENTS OF FAR-RIGHT ISRAELI MINISTERS

WASHINGTON -- The Biden administration has spoken out against the comments of two far-right Israeli ministers who recently called for Palestinians to be resettled outside of Gaza.

In a statement Tuesday, State Department spokesperson Matthew Miller called Israeli Ministers Bezalel Smotrich and Itamar Ben Gvir's comments "inflammatory and irresponsible."

On Sunday, Smotrich, Israel's far-right finance minister, said Israel should "encourage migration" from Gaza and re-establish Jewish settlements in the territory, where it withdrew settlers and soldiers in 2005. Ben Gvir has made similar comments about resettling Palestinians.

Miller said Israeli leaders, including Prime Minister Benjamin Netanyahu, have "repeatedly" told the U.S. leaders that "such statements do not reflect the policy of the Israeli government."

"Gaza is Palestinian land and will remain Palestinian land, with Hamas no longer in control of its future and with no terror groups able to threaten Israel," Miller said.