Israel struck Hezbollah targets near the city of Baalbek on Monday, killing two group members, security sources said, the first such attack on Lebanon's east since hostilities began after the Gaza war erupted.
The Israeli army said the strikes targeted Hezbollah air defence systems in retaliation for the Iran-backed group downing one of its drones in south Lebanon earlier on Monday.
"Two Hezbollah members were killed in the Israeli strikes near Baalbek," a security official in Lebanon told AFP. Another security source confirmed the toll.
Earlier Monday, one of the sources had said Israeli strikes hit a building used by Hezbollah in a Baalbek suburb, and a warehouse near Baalbek belonging to the Shiite Muslim group.
Both sources requested anonymity as they were not authorised to speak to the press.
The Israeli army said it struck Hezbollah "aerial defence" sites in the Bekaa valley in response "to the launch of a surface-to-air missile" which downed the Israeli drone.
It was the first Israeli attack on Hezbollah outside Lebanon's south since war erupted on October 7 between Israel and Palestinian militant group Hamas, a Hezbollah ally.
Since October 8, Hezbollah and its arch-foe Israel have exchanged near-daily fire, but strikes have been largely contained to the border between the two countries -- although Israel has on occasion launched strikes elsewhere in Lebanon, including in Beirut.
During a funeral procession for a Hezbollah fighter, one of the group's lawmakers, Hassan Fadlallah, lambasted the strikes on Baalbek, a Hezbollah bastion near the border with Syria.
"This Zionist encroachment will not push us to retreat, it will rather increase our determination," Fadlallah said in a televised address.
Israel's "aggression on Baalbek or any other region will not remain unanswered, and the resistance will respond in the appropriate manner," he added.
In January, a strike widely attributed to Israel killed Hamas's deputy leader Saleh al-Aruri and six militants in Hezbollah's south Beirut stronghold -- the most high-profile Hamas figure to be killed during the war.
On Sunday, Israeli Defence Minister Yoav Gallant said there would be no let up in Israeli action against Hezbollah, even if a ceasefire and hostage deal were secured in Gaza.
Hezbollah has said it will stop launching attacks on Israel if the Israeli military stops its Gaza offensive.
At least 280 people have been killed on the Lebanese side since fighting erupted, most of them Hezbollah fighters but also including 44 civilians, according to an AFP tally.
On the Israeli side, 10 soldiers and six civilians have been killed, according to the Israeli army.
IOL