Hezbollah has traded near-daily fire with Israel in support of its ally Hamas since the Palestinian militant group's October 7 attack on Israel triggered war in Gaza.
Tensions have soared in the past week as Iran and its allies vowed revenge for the high-profile killings of Hezbollah's top military commander Fuad Shukr and Hamas political leader Ismail Haniyeh, both blamed on Israel.
Lebanon's health ministry said an "Israeli enemy raid on a house in the town of Mayfadun", near the southern city of Nabatiyeh, killed five people.
The dead "were all Hezbollah fighters", a security source told AFP, requesting anonymity because the matter is sensitive.
The Israeli military said its air force "struck a Hezbollah military structure in the area of Nabatiyeh" that was being used "to advance terror attacks" against Israel.
Hezbollah claimed several attacks on Israel on Tuesday, including one with "explosive-laden drones" targeting a barracks north of the coastal town of Acre.
Israel's Magen David Adom emergency service said paramedics were treating "a 30-year-old male in serious condition and a 30-year-old woman in mild to moderate condition with shrapnel injuries... and evacuating them to the Galilee Hospital in Nahariya", near Acre.
Hezbollah said its latest attacks were in response to an air strike on the southern village of Ebba on Monday that the Israeli military said targeted a commander in the group's elite Radwan Force.
Hezbollah leader Hassan Nasrallah is set to give a televised speech at 5:00 pm (1400 GMT).
The cross-border violence since October has killed at least 555 people in Lebanon, mostly fighters but also including at least 116 civilians, according to an AFP tally.
On the Israeli side, including in the annexed Golan Heights, 22 soldiers and 25 civilians have been killed, according to army figures.
