After some of the heaviest cross-border exchanges of fire since the hostilities flared, Israel warned people to leave areas where it said the armed movement was storing weapons.
After almost a year of war against Hamas in the Gaza Strip on its southern border, Israel is shifting its focus to its northern frontier from where Hezbollah has been firing rockets into Israel in support of its ally Hamas.
Israel's military on Monday targeted Hezbollah in Lebanon's south, eastern Bekaa valley and northern region near Syria in its most widespread strikes.
Prime Minister Benjamin Netanyahu has urged Israelis to stay united amid a military campaign. (AP PHOTO)
Prime Minister Benjamin Netanyahu said Israel faced "complicated days" as it stepped up attacks against Hezbollah in southern Lebanon and called on Israelis to stay united as the campaign unfolded.
"I promised that we would change the security balance, the balance of power in the north - that is exactly what we are doing," he said in a message following a situational assessment at military headquarters in Tel Aviv.
Earlier, Israel's Defence Minister Yoav Gallant said the actions would continue until "we achieve our goal to return the northern residents safely to their homes," setting the stage for a long conflict as Hezbollah has vowed to fight on until there is a ceasefire in the Gaza Strip.
Lebanon's health ministry said at least 274 people had been killed, including 21 children, and 1024 were wounded in Israel's strikes on Monday.
Israeli army spokesman Avichay Adraee said on X that more than 300 Hezbollah targets had been struck so far after earlier warning that air strikes were imminent on houses in Lebanon where "Hezbollah hid weapons".
اثباتات جديدة ان حزب الله يخزن السلاح بين المنازل وفي المباني. — افيخاي ادرعي (@AvichayAdraee) pic.twitter.com/p1VQaicYQ3September 23, 2024
Reuters could not independently verify Israel's allegation that Hezbollah had stored weapons in homes and villages.
In response, Israel's arch foe Hezbollah said it had targeted a military base in northern Israel with dozens of missiles.
Another round of attacks was expected.
Israeli aircraft are preparing to attack Hezbollah strategic weapons stashed in houses in Lebanon's Bekaa valley, the Israeli military spokesman said, calling on civilians to leave immediately.
"The sights now from south Lebanon are of secondary explosions of Hezbollah weapons, which are exploding inside houses. In every house we are attacking there are weapons. Rockets, missiles, unmanned aerial vehicles that were meant for and aimed at killing Israeli civilians," Rear Admiral Daniel Hagari said in a televised statement.
Hezbollah has not commented on the Israeli claims it hid weapons in houses.
The air strikes have intensified pressure on Hezbollah, which last week suffered an attack its Secretary General Hassan Nasrallah called "unprecedented in the history" of the group, after thousands of pagers and walkie-talkies used by its members exploded.
The operation was widely blamed on Israel, which has not confirmed or denied responsibility.
In another major blow, an Israeli airstrike on Beirut's southern suburb on Friday targeted senior Hezbollah commanders, killing 45 people, according to the Lebanese health ministry.
Hezbollah said 16 members of the group were among the dead, including senior leader Ibrahim Aqil and another commander, Ahmed Wahbi.
