Israel-Hamas War Live Updates: Strikes in Lebanon, Palestinians Flee a Besieged Hospital

Israel carried out extensive and lethal airstrikes in southern Lebanon on Wednesday in response to a deadly rocket attack on northern Israel, escalations in recent fighting that threaten to derail diplomatic efforts to prevent a major expansion of the war in the Gaza Strip.

The rocket attack from Lebanon was the second in two days to cause casualties in northern Israel, striking a military base near the city of Safed — beyond the border zone Israel has evacuated for months because of the fighting. A soldier was killed, the military said, identifying her as serving with Israel’s border protection service. Eight other people were wounded, according to Magen David Adom, the emergency medical service.

There was no immediate claim of responsibility, but suspicion quickly fell on Hezbollah, the Lebanese militia allied with Hamas, the armed group Israel been battling in Gaza for more than four months. Hezbollah and Israel have launched dozens of tit-for-tat strikes across the border, fueling fears that the exchanges could expand to a full-fledged second front in the war.

Within hours of the rocket attack, Israel’s military said that it had carried out strikes against “a series of Hezbollah terrorist targets,” including compounds and control rooms. Lebanese broadcasters showed images and videos of smoke plumes and destruction. The state news agency reported that strikes hit at least eight areas, killing a woman and her two children; Hezbollah said that one of its fighters had also been killed, and a senior official with the group, Hashem Safieddine, vowed a response.

Israeli officials have warned repeatedly that they would take much stronger military action in Lebanon if the cross-border violence continued; Israel invaded Lebanon in 1982 and 2006 in response to such attacks.

Benny Gantz, a member of Prime Minister Benjamin Netanyahu’s emergency war cabinet, said on Monday that Israel could target the Lebanese military in addition to Hezbollah. Any incursion into Lebanon or strikes on the Lebanese military would mark a major escalation in the conflict.

“It is important that we be clear — the one responsible for the fire from Lebanon is not only Hezbollah or the terrorist elements that carry it out, but also the government of Lebanon and the Lebanese state that allows the shooting from its territory,” Mr. Gantz said, adding: “There is no target or military infrastructure in the area of ​​the north and Lebanon that is not in our sights.”

The Israeli military’s chief of staff, Lt. Gen. Herzi Halevi, cautioned that “this is not the time to stop” striking Hezbollah — which, like Hamas, is backed by Iran — and warned that “there is still a long way to go.”

Hezbollah has been equally defiant. Hassan Nazrallah, the group’s leader, said on Tuesday, “You escalate, we escalate.”

The latest strikes threatened to derail diplomatic efforts by the United States and others to defuse the cross-border tensions. A Western diplomat said on Tuesday that France had presented a proposal to Israel, Lebanon’s government and Hezbollah. The French proposal details a 10-day process of de-escalation and calls for Hezbollah to withdraw its fighters to a distance of about six miles from the border, according to the diplomat, who is involved in the talks and who requested anonymity to discuss sensitive deliberations.

The clashes between Hezbollah and Israel have displaced more than 150,000 people on both sides of the Israel-Lebanon border since the war with Hamas began.

Mr. Netanyahu has been wary of opening a second front while the Israeli military continues to press its invasion of Gaza, but he has faced calls from some of the displaced residents and political hard-liners — including some in his own far-right governing coalition — to take stronger action.

Avigdor Liberman, a former top adviser to Mr. Netanyahu who now leads an opposition party, accused the government of waving a “white flag” at Hezbollah by failing to take strong enough steps to stop the rocket attacks.

“The war cabinet surrendered to Hezbollah and lost the north,” he wrote on social media on Wednesday after the attack on Safed.

Israel’s military said that the rockets from Lebanon had landed in the areas of Netu’a, Manara and a military base near Safed, a city of nearly 40,000 people, about eight miles south of the border. Four Israeli military bases sit near Safed, and rocket warnings there are not uncommon, but fatalities and direct hits are rare, said Tamir Engel, a spokesman for the city.

In early January, Hezbollah fired rockets toward a small military base in the area. The group said that it was retaliating for the assassination days earlier of a senior Hamas commander in Lebanon; Israel said at the time that the attack had caused no casualties.

Euan Ward, Adam Sella and Johnatan Reiss contributed reporting.