The war began when Palestinian militant group Hamas launched the worst-ever attack on Israel, with Hezbollah and other Iran-backed groups around the region drawn into the violence.

Israel said it hit about 1,100 Hezbollah sites in southern and eastern Lebanon in 24 hours, including a "targeted strike" in Beirut.

A source close to Hezbollah said the strike on the capital targeted Ali Karake, the group's third in command after the killing of key commanders in earlier strikes.

Lebanese state media reported new raids in the country's east, while Hezbollah said it targeted five sites in Israel.

Israelis ran for cover when air raid sirens sounded in the coastal city of Haifa, which had been targeted a day earlier.

The Israeli strikes killed 274 people in Lebanon, including 21 children and 39 women, Health Minister Firass Abiad said, adding about 5,000 people had been wounded since Tuesday.

World powers have implored Israel and Hezbollah to pull back from the brink of all-out war, with the focus of violence shifting sharply in recent days from Israel's southern front with Gaza to its northern border with Lebanon.

"We sleep and wake up to bombardment... that's what our life has become," said Wafaa Ismail, 60, a housewife from the southern Lebanese village of Zawtar.

- More to come -

The Israeli military said it hit "approximately 800 Hezbollah terror targets in southern Lebanon and in the area of Bekaa deep inside Lebanese territory".

Israeli army chief Herzi Halevi said the strikes hit combat infrastructure Hezbollah had been building for two decades.

The military also warned people living in the Bekaa valley, in eastern Lebanon, to flee their homes, as it announced it was "broadening" the scope of its strikes.

Abiad said "thousands of families from the targeted areas have been displaced".

Explosions near the ancient city of Baalbek in eastern Lebanon sent smoke billowing into the sky.

Hezbollah said it had fired rockets at military sites near Haifa and later launched "dozens of rockets" at two Israeli bases "in response to the Israeli enemy's attacks on the south and the Bekaa".

Hezbollah, a powerful political and military force in Lebanon, has exchanged near-daily fire with Israel in support for its Palestinian ally Hamas.

- Israel changing 'security balance' -

Prime Minister Benjamin Netanyahu said Israel was acting to change the "security balance" in the north by preempting threats.

Hezbollah's deputy chief, Naim Qassem, said Sunday the group was in a "new phase, namely an open reckoning" with Israel and was ready for "all military possibilities".

They spoke after Hezbollah rocket attacks on northern Israel caused damage in the Haifa area.

The attack came after an Israeli air strike on southern Beirut Friday killed its elite Radwan Force commander, Ibrahim Aqil, and coordinated communications device blasts that Hezbollah blamed on Israel killed 39 people and wounded almost 3,000 on Tuesday and Wednesday.

"No country can live like this," said Ofer Levy, 56, a customs officer who lives near Haifa.

Since the cross-border exchanges between Israel and Hezbollah began in October, tens of thousands of people on both sides have fled their homes.

An Israeli military official, who cannot be further identified under military rules, said the military operation seeks to "degrade threats" from Hezbollah, push them back from the border, and then to destroy infrastructure near the frontier.

Lebanese Prime Minister Najib Mikati urged the United Nations and world powers to deter what he called Israel's "plan that aims to destroy Lebanese villages and towns".

- Another Gaza? -

US President Joe Biden, whose country is Israel's main ally and weapons supplier, on Monday said Washington was "working to de-escalate in a way that allows people to return home safely".

Separately, Pentagon spokesman Major General Pat Ryder said the US was "sending a small number of additional US military personnel" to the region after thousands were deployed earlier alongside warships, fighter jets and air defence systems.

Ahead of the annual General Assembly in New York, UN chief Antonio Guterres warned of Lebanon becoming "another Gaza" and said it was "clear that both sides are not interested in a ceasefire" there.

Speaking at the General Assembly, Masoud Pezeshkian, the recently elected president of Iran -- which backs Hezbollah and Hamas -- accused Israel of seeking "to create this wider conflict".

The UNIFIL peacekeeping force in south Lebanon meanwhile warned that "any further escalation of this dangerous situation could have far-reaching and devastating consequences".

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.

Of the 251 hostages also seized by militants, 97 are still held in Gaza, including 33 the Israeli military says are dead.

Israel's retaliatory military offensive has killed at least 41,455 people in Gaza, most of them civilians, according to figures provided by the Hamas-run territory's health ministry. The UN has described the figures as reliable.

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