Israel and Hezbollah threatened on Sunday to escalate their cross-border attacks despite a chorus of international calls for both sides to step back from the brink of all-out war.
Prime Minister Benjamin Netanyahu said after a night of intense rocket fire from Lebanon that Israel has dealt "a series of blows on Hezbollah that it could have never imagined".
Hezbollah was equally defiant, with the group's deputy chief Naim Qassem saying it was in a "new phase" in its battle against Israel.
They spoke nearly a year after the outbreak of the Gaza war and after attacks on northern Israel sent hundreds of thousands of people to bomb shelters and caused damage in the area of Haifa city.
"No country can tolerate attacks on its citizens," Netanyahu said nearly a year into the Gaza war sparked by Hamas's October 7 attack on Israel that has also drawn in Iran-backed groups across the region, including Hezbollah.
Defence Minister Yoav Gallant meanwhile said military actions "will continue until we reach a point where we may ensure the safe return of Israel's northern communities to their homes".
"This is our goal, this is our mission, and we will employ the means necessary to achieve it."
Israel's key ally the United States said Sunday military escalation is not in Israel's "best interest".
White House National Security spokesman John Kirby said "we still believe that there can be time and space for a diplomatic solution".
UN chief Antonio Guterres warned of the risk of Lebanon becoming "another Gaza".
Speaking ahead of the annual UN General Assembly in New York, he nonetheless added it was "clear that both sides are not interested in a ceasefire" in the Gaza war.
British Foreign Secretary David Lammy called for an "immediate ceasefire" after a "worrying escalation", and EU foreign policy chief Josep Borrell echoed the ceasefire call, saying Europe was "extremely concerned".
Hezbollah rocket fire reached Kiryat Bialik on the edge of north Israel's largest city Haifa, leaving a building in flames, another pockmarked with shrapnel and vehicles incinerated.
"This is not pleasant. This is war," said one resident, Sharon Hacmishvili.
Hamas in a statement on Sunday hailed Hezbollah for its "resilience and bravery" in attacking Israel.
Israel has signalled its intention to shift focus to Iran-backed Hezbollah after nearly a year of cross-border fire that began in October in what Hezbollah calls support for Hamas Palestinian militants fighting Israel.
Friday's Israeli air strike in a densely populated Hezbollah stronghold in southern Beirut killed the head of Hezbollah's elite Radwan Force, Ibrahim Aqil. The Lebanese health ministry said the strike killed 45 people.
It came after a series of coordinated communication device blasts on Tuesday and Wednesday that killed 39 people and wounded almost 3,000, and which have been blamed on Israel.
Speaking at Aqil's funeral in Beirut Sunday, Qassem said: "We have entered a new phase, namely an open reckoning" with Israel.
"Threats will not stop us... We are ready to face all military possibilities."
Hezbollah's Radwan Force has spearheaded its ground operations, and Israel has repeatedly called for its fighters to be pushed back from the border.
UN special coordinator for Lebanon Jeanine Hennis-Plasschaert posted on X that the region was "on the brink of an imminent catastrophe".
"It cannot be overstated enough: there is NO military solution that will make either side safer," she wrote.
The Israeli army said more than 150 rockets, missiles and drones were fired at its territory during the night and early Sunday, most from Lebanon.
It said it attacked Hezbollah targets in southern Lebanon in response and "to prevent a larger-scale attack".
Lebanon's health ministry said three people were killed in Israeli strikes on southern areas, and Hezbollah announced two fighters were killed.
Israel's civil defence agency ordered all schools in the north closed after the rocket fire.
"It reminds me of October 7 when everybody stayed home," Haifa resident Patrice Wolff told AFP.
Hezbollah said it had targeted Israeli military production facilities and an air base in the Haifa area after this week;s communication device blasts.
"In an initial response" to the explosions of the pagers and two-way radios, Hezbollah said it "bombed the Rafael military industry complexes" in northern Israel with "dozens" of rockets.
It said it targeted Ramat David airbase with Fadi-1 and Fadi-2 rockets. The site is among the deepest inside Israel so far targeted, and this appeared to be Hezbollah's first use of that rocket type during the Gaza war.
Hezbollah chief Hassan Nasrallah has acknowledged that the communication devices attack was "unprecedented". He vowed that Israel -- which has not commented on the blasts -- would face retribution.
Months of near-daily exchanges have killed hundreds in Lebanon, mostly fighters, and dozens in Israel and the annexed Golan, forcing tens of thousands on both sides from their homes.
Netanyahu on Tuesday announced an expansion of the country's war goals to include the return of northern Israeli residents.
International mediators from Qatar, Egypt and the United States have for months tried to secure a ceasefire and hostage release deal in Gaza, which diplomats repeatedly said would help calm regional tensions.
Netanyahu's critics in Israel have accused him of dragging out the war, with thousands again gathering in Tel Aviv Saturday demanding a deal to free hostages in Gaza.
Hamas's October 7 attack on Israel resulted in the deaths of 1,205 people, mostly civilians, according to an AFP tally based on Israeli official figures that include hostages killed in captivity.
Israel's retaliatory military offensive has killed at least 41,431 people in Gaza, most of them civilians, according to figures provided by the Hamas-run territory's health ministry. The UN has acknowledged the figures as reliable.
