Lebanon's Hezbollah launched rockets at Israel after an Israeli air strike that according to a Lebanese security source killed two civilians in the country's south.
The Israeli military, whose forces have been trading regular cross-border fire with Hezbollah since early October, said its raid had targeted two operatives from the Iran-backed group.
The Shiite Muslim movement said it had retaliated by launching dozens of rockets at the border town of Kiryat Shmona, in Israel's north.
The Israeli military said four soldiers were wounded including one "severely", after air defences intercepted most of the "approximately 15 launches... identified crossing from Lebanon".
Israeli aircraft then "struck a Hezbollah field commander who was operating in the area of (Kfar) Tebnit in southern Lebanon", the military added.
Lebanon's official National News Agency (NNA) reported multiple wounded in an Israeli drone strike on a vehicle near Kfar Tebnit.
Hezbollah had already launched multiple attacks against Israeli military positions along the border on Saturday.
The Lebanese security source, requesting anonymity as they were not authorised to speak to the media, said that "two civilians were filling up water from a roadside spring" in south Lebanon's Deir Mimas area when they were killed in an "Israeli air strike".
A source close to Hezbollah, also requesting anonymity, said one of the men was a member of the group and the father of a fighter who had been killed, while the second man was a member of Hezbollah ally the Amal movement.
The pair were "civilians, not fighters", the source added.
The Israeli army said in a statement that "soldiers identified two Hezbollah terrorists preparing to launch projectiles toward Israeli territory in the area of Deir Mimas in southern Lebanon".
"Shortly following the identification, the IAF (air force) struck the terrorists," the statement added.
Hezbollah said it had launched rockets "in response to the aggressions by the Israeli enemy against the villages... and civilians in the south".
Hezbollah has traded almost daily fire with Israeli forces in support of ally Hamas since the Palestinian militant group's October 7 attack on Israel triggered war in the Gaza Strip.
The NNA said an "enemy drone" killed two men on Saturday in the same area, identifying one of them as a local council member for the Amal movement in the nearby village of Kfar Kila.
It said they were collecting water from the spring "to take it for livestock in Kfar Kila".
The Amal movement released a statement saying one of its members, born in 1964, was killed.
In Lebanon, the cross-border violence since October has killed more than 500 people, mostly fighters but also including more than 90 civilians, according to an AFP tally.
On the Israeli side, at least 29 people have been killed, the majority of them soldiers, according to the authorities.
The violence, largely restricted to the border area, has raised fears of all-out conflict between the foes, which last went to war in the summer of 2006.