Hezbollah's second-in-command warned on Saturday that an all-out war by Israel aimed at returning 100,000 displaced people to their homes in areas near the Lebanon border would displace "hundreds of thousands" more.
Naim Qassem, number two in the Iran-backed Lebanese group, was speaking after Defence Minister Yoav Gallant said Israel was determined to restore security to its northern front.
Gallant told Israeli troops last week that "we are preparing for anything that may happen in the north".
In a speech in Beirut, Qassem said: "We have no intention of going to war, as we consider that this would not be useful.
"However, if Israel does unleash a war, we will face up to it -- and there will be large losses on both sides," he said.
"If they think such a war would allow the 100,000 displaced people to return home ... we issue this warning: prepare to deal with hundreds of thousands more displaced."
Hezbollah has traded near-daily fire with Israeli forces in support of ally Hamas since the Palestinian militant group's October 7 attack on Israel triggered war in Gaza.
Thousands of people living in the border area of both countries have been displaced by the fighting.
On Saturday evening, the Israeli military said its air force had struck suspected Hezbollah weapons storage facilities at two locations in Lebanon's eastern Beqaa Valley, as well as in six locations in the south.
Three children were among four people wounded in an Israeli strike in the northern Beqaa's Hermel district, some 140 kilometres (85 miles) from the Israeli border, the Lebanese health ministry said.
A source close to Hezbollah said the strike targeted a farm in the area, a stronghold of the militant group.
A second strike on the village of Serine, near Baalbek, targeted "warehouses storing food products", the source added.
The cross-border violence since early October has killed 623 people in Lebanon, mostly fighters but also including at least 142 civilians, according to an AFP tally.
On the Israeli side, including in the annexed Golan Heights, authorities have announced the deaths of at least 24 soldiers and 26 civilians.