“The smell of death is everywhere as bodies are left lying on the roads or under the rubble,” Mr. Lazzarini said of northern Gaza. “Missions to clear the bodies or provide humanitarian assistance are denied. In northern Gaza, people are just waiting to die.”

Gloria Lazic, an aid worker with the U.N. agency for humanitarian coordination, OCHA, said Tuesday on social media that requests by the agency to help people trapped under the rubble in the Faluja area of Jabaliya, in northern Gaza, had been “repeatedly denied by Israeli authorities” over five days, imperiling the lives of potential survivors.

“We’re talking about more than 40 people, three families, who have seen their houses collapse above them,” Ms. Lazic said. “And we don’t know if we finally get this approval, how many will still be alive.”

On Tuesday, the Gazan Health Ministry, which does not distinguish between civilian and combatant deaths, said that Israeli attacks over the last two days had killed 115 people and injured more than 480 others. Some victims, the ministry said, were still under the rubble.

COGAT, the Israeli agency that oversees policy for the Palestinian territories, did not immediately respond to a query about Ms. Lazic’s post about being denied permission to search for survivors.

But COGAT recognized the international community’s alarm about the dire situation in Gaza. Last week, in an emergency U.N. Security Council meeting, Council members displayed rare unity, unanimously calling on Israel to immediately address a falloff of aid and supplies reaching the enclave.

The United States on Oct. 13 also warned Israel in a letter that it risked losing military assistance if it failed both to increase aid flow into Gaza and to comply with its humanitarian obligations.

On Tuesday, COGAT and the Israeli military said in a joint statement that since Oct. 14 — the day after the United States issued the warning letter — more than 230 trucks with food, water, medical supplies and shelter equipment from Jordan and the international community had been transferred to northern Gaza. The Israeli authorities “will continue to act in accordance with international law to facilitate and ease the humanitarian response to the Gaza Strip,” the statement said.

In a separate update on humanitarian assistance in Gaza issued by COGAT on Tuesday, it said that 478 aid trucks had entered the enclave from Oct. 14 to Oct. 20.

The latest numbers still fall far short of the minimum amount of assistance that experts say is required to meet the needs of the 2.2 million people in the besieged enclave. At least 350 aid trucks per day must be allowed to enter Gaza, the U.S. warning letter to Israel said.

COGAT has argued that U.N. agencies are not moving the aid that reaches the enclave. In a post on social media on Monday, COGAT said there were “600 trucks worth of aid waiting to be picked up and distributed, the majority by @UN aid agencies.”

Disputes between COGAT and U.N. agencies over aid in Gaza have persisted throughout the war. But hunger in northern Gaza has worsened, and the World Food Program this month said there was a risk of famine for the roughly 400,000 people living under bombardment there.

Mr. Safieddine, a cousin of Mr. Nasrallah and one of Hezbollah’s top officials, was presumed to be at that meeting.

On Tuesday, the Israeli military said Mr. Safieddine was killed in a strike about three weeks ago. Mr. Safieddine had a significant influence over Hezbollah and served as the group’s leader when his cousin, Mr. Nasrallah, was not in Lebanon, according to a statement from the Israeli military.

“Throughout the years, Safieddine directed terrorist attacks against the state of Israel and took part in Hezbollah’s central decision-making processes,” the statement said, adding that more than 25 Hezbollah operatives were present at the meeting where the military struck and killed Mr. Safieddine.

The Israeli military did not provide any proof for its assertion that Mr. Safieddine was dead.

Hezbollah has generally avoided commenting on his fate in the weeks since the strike. There was no immediate comment from Hezbollah.

“We have reached Nasrallah, his replacement and most of Hezbollah’s senior leadership,” Lt. Gen. Herzi Halevi, chief of the general staff of the Israeli military, said in a statement. “We will reach anyone who threatens the security of the civilians of the state of Israel.”

Mr. Safieddine’s death would come as yet another crushing blow for Hezbollah, which many in Lebanon now consider rudderless amid the Israeli assassination campaign against its leaders.

On Oct. 7, Prime Minister Benjamin Netanyahu suggested that Israel had killed Mr. Safieddine, but stopped short of naming him.

“We took out thousands of terrorists, including Nasrallah himself and Nasrallah’s replacement,” Mr. Netanyahu had said, an apparent reference to Mr. Safieddine.

The loss is another blow to Hezbollah’s leadership ranks, which have been decimated in Israel’s expanding campaign against the Iranian-backed group.

Mr. Safieddine, born in southern Lebanon in the early 1960s, was one of Hezbollah’s earliest members. He joined after the Shiite group was formed, with Iranian guidance, in the 1980s during Lebanon’s civil war. He rose quickly in the group alongside Mr. Nasrallah, playing many roles and serving as a political, spiritual and cultural leader. He also led Hezbollah’s military activities at one point.

Like Mr. Nasrallah, Mr. Safieddine usually appeared in a black turban, marking him as a revered Shiite cleric who could trace his ancestry back to the Prophet Muhammad. And like his cousin, Mr. Safieddine studied in Iran: He pursued religious studies in the city of Qom before returning to Lebanon to work for Hezbollah.

He was close friends with Maj. Gen. Qassim Suleimani, who commanded the Islamic Revolutionary Guards Corps’ Quds Force in Iran until the United States killed him in an airstrike in Baghdad in 2020. Later that year, Mr. Safieddine’s son married the Iranian general’s daughter in a much-publicized wedding that some analysts and critics point to as emblematic of Iran’s entrenchment in Hezbollah.

The United States and Saudi Arabia designated Mr. Safieddine a terrorist in May 2017 for his Hezbollah leadership role. At the time, the State Department described him as “a senior leader” in Hezbollah’s Executive Council, which oversees the group’s “political, organizational, social and educational activities.”

The United States had designated Hezbollah a terrorist organization two decades earlier, and holds the group responsible for several attacks that killed hundreds of Americans, including the bombings of the American Embassy and U.S. Marine barracks in Beirut in the early 1980s, and the 1985 hijacking of TWA Flight 847.

Farnaz Fassihi, Euan Ward and Aaron Boxerman contributed reporting.

Photographs published in the Israeli news media on Tuesday showed damage to an upstairs window of the Netanyahus’ Caesarea home, as well as damage to the grounds.

The couple are known to have often spent weekends at their home in Caesarea, a well-to-do coastal town. Their locations are more often kept secret nowadays, for security reasons.

Mr. Netanyahu has called the episode a “grave mistake,” and his allies have warned that it will not go unanswered.

After the prime minister met on Tuesday with Secretary of State Antony J. Blinken in Jerusalem, Mr. Netanyahu’s office said Mr. Blinken had “expressed the U.S.’s deep shock over the Iranian attempt, via Hezbollah, to eliminate the Prime Minister of Israel, and made it clear that this was an exceptionally extreme incident.” Mr. Netanyahu thanked Mr. Blinken and said that this was “a dramatically significant issue that must not be ignored,” the statement added.

Also on Tuesday, in what appeared to be an implicit effort to distance Iran from responsibility for the attack, Hezbollah, at war with Israel, said it was fully responsible for the drone strike. Mohammad Afif, Hezbollah’s media chief, made the claim at a news conference.

Hezbollah’s statement comes as Israel is preparing for an attack on Iran in retaliation for Iran’s recent launching of nearly 200 ballistic missiles at Israel. That assault, in turn, came in response to the assassinations of Hezbollah’s leader, Hassan Nasrallah, in September; Hamas’s political leader, Ismail Haniyeh, during a visit to Tehran in July; and an Iranian commander.

The Israeli military’s chief spokesman, Rear Adm. Daniel Hagari, said in a televised statement on Saturday night that “the fighting will only increase” after that morning’s drone strike, which he characterized as an “attempt to harm the prime minister.”

The military had said only that the drone struck “a building” in Caesarea, without elaborating.

The strike on the house underlines the challenge unmanned vehicles pose to Israel’s air defense. Drones can carry out precise strikes, and are difficult to detect and intercept, in part because they fly at low altitudes.

The strike in Caesarea came nearly a week after a Hezbollah drone attack killed four soldiers and wounded dozens of others as they sat in the dining hall of a military base in northern Israel.

The suspects were arrested in recent weeks and have yet to be indicted, it said, describing them as residents of Israel. They were from the Beit Safafa neighborhood, which is populated mainly by Palestinians.

Some of the suspects took photographs of the scientist’s house in preparation for the assassination attempt, according to the statement, which said they also had planned to blow up a police vehicle and throw a grenade at a house in return for the equivalent of around $50,000 in total.

The statement gave few details of the identities of the suspects but it said that one, a 23-year-old Israeli citizen, had recruited the others. They were then directed to spray graffiti in a different part of Jerusalem, set fire to cars and gather intelligence, the statement said. The statement gave no reason for why those targets were suggested.

The statement came a day after the police said they had dismantled a different spy network made up of seven Jewish Israelis who were gathering intelligence for Iran. It was not clear when the suspects were arrested or why both spy cases were made public this week.

Israel’s government has said it will retaliate against Iran for a drone and missile attack carried out against Israel on Oct. 1. Direct conflict between Israel and Iran broke out in April after a clandestine war that had lasted for decades.

The English language version of Iran’s state news agency, IRNA, has made no mention of the two cases or carried any response from the Iranian authorities to the allegations.

The neighborhood where the suspects lived is mostly part of East Jerusalem, which was captured by Israel from Jordan in 1967 and later annexed. Israel considers all of Jerusalem its undivided capital, but most East Jerusalem residents are Palestinians who want East Jerusalem to be the capital of a future Palestinian state. The United Nations Security Council has deemed it occupied territory.

The police said on Tuesday that, following a separate investigation with other Israeli security agencies, they have recently indicted a man who was planning to attack a demonstration on behalf of hostages held in Gaza. It gave no further details of that plot.

“We’re hearing his phone ringing. It keeps ringing under the rubble,” said Mpsati Mi, 30, an Ethiopian national who was searching for her friend, Aamal.

“He’s not only a neighbor, but a brother to me,” she said.

“I tried to call,” said another local resident, Ahmad Kalash, a Syrian national who had already visited nearby hospitals to see if he could find his friend, Hussein.

“I’m waiting to hear anything from the rescuers,” he said.

At least 18 people, including four children, were killed in the strike, and 60 others were wounded, according to Lebanon’s health ministry. The attack, which was not preceded by an evacuation notice from the Israeli military, also damaged the nearby hospital, which in recent weeks has been swamped by patients evacuated from other health facilities.

The Israeli military said that it had not targeted the hospital, and had instead aimed at a “Hezbollah terror target” in the area. The military said that the hospital had not been affected, but damage was seen during a visit to the facility by a Times reporter and photographer on Tuesday.

The powerful blast had shattered the hospital’s windows and the solar panels affixed atop the building, a lifeline amid Lebanon’s chronic power shortages. Rows of sand bags now lined the underground parking lot as hospital workers made preparations for further strikes. Many of them were in an uproar, saying they did not have the staff numbers and supplies they needed.

“The hospital was subjected to severe damage,” said Dr. Jihad Saadeh, the hospital’s director, recounting how two missiles had flattened at least three buildings opposite the main gate.

Israel began an intensified military campaign against Hezbollah last month, nearly a year after the Lebanese militant group began firing rockets into Israel in solidarity with Hamas in Gaza. The Israeli offensive has set off a humanitarian crisis in Lebanon, displacing around a fifth of the population and buckling the country’s health sector.

The conflict has killed more than 2,400 Lebanese over the past year, most of them in recent weeks, according to Lebanon’s health ministry. Hundreds of women and children are among the dead.

At the scene of the strike, one man said he had lost eleven of his relatives — among them women and children. Other local residents described panic and terror when the overnight strike hit, and said that people who had been displaced from other parts of the country by Israel’s offensive were among the dead.

“The shock wave pushed us. I felt I was flying,” said Ahmad al-Hassan, 48, who was at home with his wife and children when the blast struck. His home survived the explosion but was badly damaged. He was one of the lucky ones.

Hassan Hakim stood waiting at the site for news about his friend, Mohamed, who was still trapped under the rubble along with his two children.

“I saw a hand,” said Mr. Hakim. “I don’t know whether it’s Mohamed or not.”

The information in the documents is highly classified and details interpretations of satellite imagery that shed light on a possible strike by Israel on Iran. They began circulating on Friday on the Telegram app. U.S. officials have previously said they did not know from where the documents had been taken, and that they were looking for the original source of the leak.

In a statement, the F.B.I. said it was “working closely with our partners in the Department of Defense and intelligence community. As this is an ongoing investigation, we have no further comment.” The bureau is responsible for investigating violations of the Espionage Act, which outlaws the unauthorized retention of defense-related information that could harm the United States or aid a foreign adversary.

Israel has made it clear it intends to retaliate for an Iranian missile barrage on Oct. 1. Iran’s Islamic Revolutionary Guards Corps said that the strike was launched after the assassinations of Hezbollah’s leader, Hassan Nasrallah, in Lebanon; Hamas’s political leader, Ismail Haniyeh, killed in Tehran in July; and an Iranian commander. U.S. officials believe the strike could take place in the coming days.

Mr. Gallant told Mr. Blinken that Israeli strikes against Hezbollah would continue even after the ground invasion of Lebanon ended and “until it is possible to ensure the safe return of Israel’s northern communities to their homes, and the withdrawal of Hezbollah forces from southern Lebanon,” the minister’s office said in a statement.

With the prime minister, Mr. Blinken discussed “the need to capitalize” on Mr. Sinwar’s death “by securing the release of all hostages and ending the conflict in Gaza,” Matt Miller, the State Department spokesman, said in a statement. Mr. Netanyahu similarly said Mr. Sinwar’s death “may positively impact” those goals.

The leader of Hamas, Mr. Sinwar was killed last week by Israeli forces during a chance encounter in Rafah. He had been Israel’s No. 1 target after he plotted the attack last October that killed roughly 1,200 people in Israel, captured some 250 hostages and ignited the war in Gaza. After that, he had steered Hamas’s hard-line stance in truce talks.

Since Mr. Sinwar’s killing, Israeli officials and mediators have been tossing around new ideas for a proposal that would pause fighting with Hamas, free at least some of the dozens of hostages remaining in Gaza and bring home the bodies of captives who are presumed dead by the Israeli authorities.

The war has defied a yearlong diplomatic effort by the Biden administration — including numerous trips to the region by senior officials including Mr. Blinken — to clinch a deal to end it. Instead the violence has widened, escalating into a full-blown war between Israel and Hezbollah in Lebanon, and direct strikes by Iran against Israeli territory.

Mr. Netanyahu has vowed that the war in Gaza will not end until Hamas is destroyed. Hamas has vowed to continue fighting unless Israel agrees to a permanent cease-fire and the complete withdrawal of its forces from Gaza.

One possibility discussed by Israel’s security cabinet in recent days was a truce of roughly a week and a half, similar to the weeklong truce between Israel and Hamas last November that saw more than 100 hostages and 240 Palestinian prisoners freed, according two Israeli officials, who spoke on condition of anonymity because they were not authorized to speak to the news media.

But it is far from clear such a pause would be acceptable to Hamas, which has vowed to hold onto the remaining hostages until Israel ends its devastating offensive in Gaza. The group has also yet to announce a new leader to replace Mr. Sinwar, who dominated its decision-making.

Israeli forces have pressed on with their campaign in Gaza in an attempt to root out what they say is a renewed Hamas insurgency in Jabaliya, in the north. Little aid has entered northern Gaza through Israeli-controlled crossings since the beginning of the month, leading humanitarian officials to warn of a brewing crisis in the already-devastated zone.

Mr. Blinken “emphasized the need for Israel to take additional steps to increase and sustain the flow of humanitarian assistance into Gaza and ensure that assistance reaches civilians throughout Gaza,” the State Department said, something the U.S. demanded of Israel in a letter earlier this month warning that U.S. military aid could be at risk.

But Mr. Netanyahu’s statement, by contrast, made no mention of any such commitment to fulfill those concerns.

The high-level American visit also came ahead of a much-anticipated Israeli attack on Iran, which fired roughly 180 ballistic missiles at Israel in early October. The barrage was a response to Israel’s assassination of senior officials aligned with Iran, including Mr. Sinwar’s predecessor.

The two leaders also talked about “the need to deter further regional aggression from Iran and its proxies,” Mr. Miller said. He did not provide any further details.

Patrick Kingsley contributed reporting from Jerusalem.

In January, Mr. Netanyahu said that his government did not support plans to build settlements on the ruins of Gaza. His opposition likely stems from concerns that re-establishing settlements could complicate Israel’s security situation and damage its standing abroad, as settlements are considered illegal under international law. Israel also faces frequent criticism for the hardships Palestinians endure under Israeli military rule and the presence of settlers in the West Bank.

But as the war against Hamas continues with no end in sight, and amid uncertainty about Israel’s postwar plan, some in the Israeli leader’s coalition want to put pressure on him to reverse, or at least soften, his position on reviving Jewish settlements in Gaza.

“Everyone in Likud supports this as an idea,” said Avihai Boaron, a member of the Knesset from the Likud party who attended the event. “Our job now is to legitimize this as a plan.”

For much of the world, the settlements, which were dismantled in Israel’s 2005 withdrawal from Gaza, were viewed as a barrier to resolving the conflict — a stance that continues to apply to those in the West Bank.

But for settler activists who believe the Gaza Strip is part of a biblical land promised to the Jewish people, leaving it in 2005 wasn’t just a mistake: it was a sin. They argue that if a Jewish civilian population had remained there, protected by the military, Hamas would not have been able to carry out the brutal attack on Israel on Oct. 7.

Rebuilding Jewish settlements in Gaza, they now say, is the only thing that can ensure the security of Israelis. “This will prevent the next massacre,” said Yinon Goldstein, 23, a West Bank settler who is part of an activist group that aspires to establish New Gaza, or a Jewish metropolitan area in place of the devastated Palestinian Gaza City.

Polling since the beginning of the war has suggested that the majority of Israelis aren’t persuaded by these arguments, and some security experts disputed these claims, saying that the real motivations for building settlements in Gaza are religious, not practical.

Behind the main stage, later taken by Mr. Ben-Gvir, Israel’s national security minister — who praised efforts to encourage Palestinians to leave Gaza — and Mr. Smotrich, the finance minister, who vowed to reintroduce Jewish settlements in Gaza, clouds of smoke rose from a distant Palestinian town in the enclave, accompanied by the thunderous roar of artillery fire. Yet, the attendees seemed to pay little notice.

Most came for the day, but a group of about 10 settler activists hoping to be the first to rebuild in Gaza has been camping for several months a short drive from there — near a highway, under a concrete bridge, a mile and a half from the northeast corner of the Gaza border.

A squad of soldiers, still dusty from fighting in northern Gaza, stopped by for coffee. Their officer, Yaron Arkash, 24, asked one of the settlers camping there who in the government was pushing for resettling Gaza.

“If I could,” Mr. Arkash said, “I’d build a home there in a heartbeat.”

The deaths of the Lebanese soldiers highlighted the complicated dynamic that Lebanon’s army is navigating as Israel invades its territory to fight Hezbollah, an Iranian-backed militant and political group with significant influence in the country.

The Lebanese Army is not a party to the conflict between Israel and Hezbollah. Still, Lebanon’s military does not support Israel’s invasion of its country, and referred to Israel as the “enemy” in statements on Sunday and Monday about the soldiers’ deaths, saying they were targeted when they were driving in an army vehicle in southern Lebanon.

By contrast, the Israeli military said in a statement that it is “not operating against the Lebanese Army and apologizes for these unwanted circumstances.”

It was the third time this month that Israeli troops have killed Lebanese soldiers amid Israel’s war with Hezbollah. And the incident came just a day before the Commander Gen. Joseph Aoun of the Lebanese Armed Forces met with Amos Hochstein, President Biden’s envoy on the Israel-Hezbollah conflict, to discuss the situation in Lebanon and “ways to support the Lebanese Army.”

American officials have expressed hope that Israel’s attacks will weaken Hezbollah, which the United States considers a terrorist organization, and loosen the group’s hold on Lebanese institutions and society. The United States has provided financial and training support to Lebanon’s armed forces, amounting to more than $3 billion since 2006.

But if the Lebanese army were to get drawn into Israel’s conflict with Hezbollah, the United States would find itself in the awkward position of having two American-supported militaries fighting each other.

“It’s already tricky where you have U.S.-backed forces killing U.S.-backed forces,” said Jennifer Kavanagh, a senior fellow and director of military analysis for Defense Priorities, a Washington think tank.

The risk of Lebanon’s army entering the fray is low, Ms. Kavanagh said. The army has long maintained a position of neutrality that has given it legitimacy with international players like the United States, which it would quickly lose if it joined the fight, she said.

“It would be difficult for the U.S. to fund the Lebanese Armed Forces if they fight Israel,” she said.

And Lebanon’s army adopted its neutral position in part because it is “extremely weak” economically and otherwise, Ms. Kavanagh said. Lebanon has been in a severe economic crisis since 2019, leaving the army scrambling to recruit, pay salaries, train and get equipment, and it is no match for either Israel or Hezbollah, she said.

But she said the view that Israel’s war against Hezbollah could prove advantageous for Lebanon in the long term is held mostly by those outside the country. The Lebanese army does want to be stronger, she said, but Israel “just taking out Hezbollah positions isn’t going to get it there.”

The Lebanese army was supposed to work with United Nations peacekeepers to ensure that Hezbollah militants could not operate in southern Lebanon, according to a 2006 U.N. Security Council resolution, known as 1701, that ended the last war between Israel and Hezbollah. The army has been criticized for failing to enforce the terms of that resolution, which international diplomats are now seeking to revive.

In his visit to Lebanon on Monday, Mr. Hochstein, the American envoy, pledged to support Lebanon’s reconstruction if the U.N. resolution is enforced, seeming to suggest that the United States wants the Lebanese government to push for Hezbollah’s disarmament in southern Lebanon, and to deploy more Lebanese troops in its place.

But the army still plays an important role in Lebanon even if it is not undertaking the traditional job of a military to maintain its country’s territorial integrity. As long as Israel maintains its position that it is not at war with Lebanon or its people and is targeting only Hezbollah — and if Lebanon argues that it doesn’t have effective control over Hezbollah, from a legal perspective — the two states are not in an armed conflict and the army’s primary role is focused inward, experts say.

“Its role is to protect the state and its people, to protect Lebanese civilians,” said Noha Aboueldahab, an assistant professor of international law at Georgetown University in Qatar. “They need to play a humanitarian role for civilians.”

Euan Ward contributed reporting.