BEIRUT — Lebanon’s Hezbollah group confirmed on Saturday that its leader and one of its founding members, Hassan Nasrallah, was killed in an Israeli airstrike in a southern suburb of Beirut.

The killing of the powerful militant group’s longtime leader sent shockwaves throughout Lebanon and the Middle East, where he has been a dominant political and military figure for more than three decades.

Nasrallah’s Assassination Escalates Middle East Conflict

Nasrallah, linked by Israel to numerous deadly attacks on Israeli and Jewish targets, has been on Israel’s kill list for decades. His assassination is by far the biggest and most consequential of Israel’s targeted killings in years, and significantly escalates the war in the Middle East. The Israeli military said it carried out a precise airstrike on Friday while Hezbollah leaders were meeting at their headquarters in Dahiyeh, south of Beirut.

Immediately after the confirmation from Hezbollah, people starting firing in the air in Beirut and across Lebanon to mourn Nasrallah’s death.

“Wish it was our kids, not you, Sayyid!” said one woman, using an honorific title for Nasrallah, as she clutched her baby in the western city of Baabda.

“We don’t believe he is killed,” a woman draped in black tearfully told al-Manar TV in Bekaa, western Lebanon. “We don’t. We left our homes and came here for him and for the resistance.”

Related Story: Israel Says It Struck Hezbollah’s Headquarters in Huge Explosion That ...

Netanyahu Hails Nasrallah’s Killing as Essential to Israel’s Goals

In his first public remarks since the killing, Prime Minister Benjamin Netanyahu said Israel’s targeting of Nasrallah was “an essential condition to achieving the goals we set.”

“He wasn’t another terrorist. He was the terrorist,” Netanyahu said.

Netanyahu said Nasrallah’s killing would help bring displaced Israelis back to their homes in the north and would pressure Hamas to free Israeli hostages held in Gaza. But with the threat of retaliation high, he warned the coming days would bring “significant challenges” and warned Iran against trying to strike.

“There is no place in Iran or in the Middle East that Israel’s long arm cannot reach. And today you know how much that is true,” he said.

The Lebanese Health Ministry said six people were killed and 91 injured in the strikes Friday that leveled six apartment buildings. Ali Karki, the commander of Hezbollah’s Southern Front, and other commanders were also killed, the Israeli military said.

A statement from Hezbollah said Nasrallah — who led the group for more than three decades — “has joined his fellow martyrs.” The group vowed to “continue the holy war against the enemy and in support of Palestine.”

Related Story: Netanyahu, at UN, Vows That Israel Will Keep ‘Degrading Hezbollah’ ...

Cross-Border Aggression Intensifies

Hezbollah started firing rockets on Israel in support of Gaza on Oct. 8, a day after Hamas militants launched an unprecedented attack on Israel, killing some 1,200 people and abducting another 250. Since then, the two sides have been engaged in escalating cross-border strikes.

Israel has vowed to step up pressure on Hezbollah until it halts its attacks that have displaced tens of thousands of Israelis from communities near the Lebanese border. The recent fighting has also displaced more than 200,000 Lebanese in the past week, according to the United Nations.

Earlier this month, thousands of explosives hidden in pagers and walkie-talkies used by Hezbollah detonated, killing dozens of people and maiming thousands, including many civilians. Israel is widely believed to be behind the attack. Israel has killed several other top Hezbollah commanders in Beirut, especially in the past two weeks, in addition to the attack that killed Nasrallah.

In Beirut’s southern suburbs, smoke rose and the streets were empty Saturday after the area was pummeled overnight by heavy Israeli airstrikes. Shelters were overflowing with displaced people. Many families slept in public squares, on beaches or in their cars. On the roads leading to the mountains above the capital, hundreds of people could be seen fleeing on foot, holding infants and whatever belongings they could carry.

Related Story: Netanyahu Says Israel Will Not Stop Striking Hezbollah Until All Its Goals Are ...

Hezbollah’s Allies Mourn and Vow Retaliation

The Palestinian militant group Hamas sent condolences to its ally, Hezbollah, and said “assassinations will only increase the resistance in Lebanon and Palestine in determination and resolve.”

Iran’s supreme leader announced five days of public mourning and Ayatollah Ali Khamenei called Nasrallah “the flag-bearer of resistance” in the region.

Hundreds of protesters took to the streets of Tehran, waving Hezbollah flags and chanting “Death to Israel” and “Death to Netanyahu the murderer.”

Thomas Juneau, a professor at the University of Ottawa’s Graduate School of Public and International Affairs, said Iran will be under significant pressure to respond to Nasrallah’s killing without escalating violence in the region.

“Iran understands that its military options are limited, given the conventional military superiority of Israel and the U.S.” Juneau told The Associated Press.

Israel Vows to Keep Up Attacks on Hezbollah

Israel’s Chief of Staff, Lt. Gen. Herzi Halevi, said Saturday that the killing of Nasrallah was “not the end of our toolbox,” indicating that more strikes were planned. Defense Minister Yoav Gallant called it “the most important targeted strike since the founding of the State of Israel.” Late Saturday, Gallant’s office said he was meeting with top army commanders to discuss the expansion of military activities along Israel’s northern front.

The military said Saturday it was mobilizing three more battalions of reserve soldiers to serve across the country. It already sent two brigades to northern Israel to prepare for a possible ground invasion.

Israeli military spokesman Lt. Col. Nadav Shoshani said Israel has inflicted heavy damage on Hezbollah’s capabilities over the past week by targeting immediate threats and strategic weapons, such as larger, guided missiles. But he said much of Hezbollah’s arsenal remains intact and that Israel would continue to target the group.

Air raid sirens sounded across central Israel on Saturday afternoon, including at the Tel Aviv international airport, shortly after Netanyahu returned from a trip to the U.S.

The Israeli military said it intercepted a missile launched from Yemen. Houthi rebels based in Yemen later said they were behind the attack targeting Ben Gurion Airport.

The Israeli military updated guidelines for Israeli citizens, canceling gatherings of more than 1,000 people due to the threat.

Approximately 60,000 Israelis have been evacuated from their homes along the Lebanese border for almost a year. This month, Israel’s government said halting Hezbollah’s attacks in the country’s north to allow residents to return to their homes is an official goal.

Continuing Strikes on Both Sides of the Border

On Saturday morning, the Israeli military carried out more than 140 airstrikes in southern Beirut and eastern Lebanon’s Bekaa Valley, including targeting a storage facility for anti-ship missiles in Beirut suburb of Dahiyeh. Israel said the missiles were stored beneath civilian apartment buildings. Hezbollah launched dozens of projectiles across northern and central Israel and deep into the Israel-occupied West Bank, damaging some buildings in the northern town of Safed.

The Israeli army again warned Lebanese residents to stay away from Hezbollah combat equipment and facilities, including in the southern suburbs of Beirut and southern Lebanon. The U.S. State Department issued an alert urging American citizens to leave the country.

A total of 1,030 people — including 156 women and 87 children — have been killed in Israeli strikes in Lebanon in less than two weeks, the country’s health minister said Saturday.