The Israeli military said its air force has been striking targets of the militant Hezbollah group “deep inside Lebanon”, where residents reported explosions near the north-eastern city of Baablek.
At least two people were killed in the strikes, a Hezbollah official said.
The strikes are among the deepest into Lebanon since the Israel-Hamas war began more than four months ago.
They come a day after Israel’s defence minister Yoav Gallant vowed to step up attacks on Lebanon’s Hezbollah even if a ceasefire is reached with Hamas in the Gaza Strip.
Lebanese security officials said Israel’s air force carried out three air strikes on the outskirts of the village of Buday, near Baalbek, targeting a convoy of trucks.
Buday is a Hezbollah stronghold. There was no immediate word on casualties.
A Hezbollah official confirmed that three strikes hit near Baalbek. He said the strikes killed at least two people and that one hit a warehouse for food products that is part of Hezbollah’s Sajjad Project that sells to people in its stronghold at prices lower than on the market.
The air strikes near Baalbek came hours after Hezbollah said its fighters on Monday shot down an Israeli drone over its stronghold in a province in southern Lebanon.
Another missile fired by Hezbollah towards the drone was intercepted by Israel, and landed near a synagogue in a town close to Nazareth in northern Israel. There were no injuries or damage.
The Israeli army said in a statement that its fighter jets struck sites used by Hezbollah in the eastern Bekaa Valley. It said they were in retaliation for Hezbollah’s firing of a surface-to-air missile at the Israeli drone.
Hezbollah has been exchanging fire with Israeli troops along the border since the Israel-Hamas was broke out in October.
The strike on Baalbek, because of its location deep inside Lebanon, is the most significant one since the early January air strike on Beirut that killed top Hamas official Saleh Arouri.
Hezbollah, which has been exchanging fire with Israel throughout the war in Gaza, has said it will halt its nearly daily attacks on Israel if a ceasefire is reached in Gaza.
But Mr Gallant said on Sunday that anyone who thinks a temporary ceasefire for Gaza will also apply to the northern front is “mistaken”.
Western diplomats have brought forward a series of proposals for a cessation of hostilities between Israel and Hezbollah, most of which would hinge on Hezbollah moving its forces at least four miles away from the border.
This will come in addition to a beefed-up Lebanese army presence, and negotiations for Israeli forces to withdraw from disputed points along the border where Lebanon says Israel has been occupying small patches of Lebanese territory since it withdrew from the rest of country’s south in 2000.
Hezbollah has signalled a willingness to entertain the proposals but has said there will be no deal in Lebanon before there is a ceasefire in Gaza.