Lebanese official media said a civilian was killed on Tuesday in an Israeli strike in the country's south, with the local water company saying he was an employee, as cross-border violence escalates.

The death came after Lebanon's Hezbollah militant group said it targeted an Israeli military position following overnight strikes in eastern Lebanon that killed three of its fighters, hours after the Iran-backed movement downed an Israeli drone.

The official National News Agency said that "an enemy drone carried out a strike" in Naqura, a coastal town on the Israeli border, later reporting that a "civilian who was seriously wounded" in the raid had died.

The agency published a statement from the South Lebanon Water Establishment announcing that one of its employees was killed "while he was carrying out his duty to ensure the continuity of the water supply" in Naqura.

The statement urged official and international bodies to condemn the strike and pressure Israel "to stop its attacks on vital and relief sector employees and workers immediately".

Hezbollah meanwhile announced the death of three of its fighters, while a source close to the group, requesting anonymity, said they were killed overnight in east Lebanon's Hermel area.

An AFP correspondent said a building in the Hermel region was completely destroyed.

The Shiite Muslim movement claimed several attacks on Israeli troops and positions on Tuesday, including two that came "in response" to Israeli attacks in eastern and southern Lebanon.

A Hamas ally, Lebanon's Hezbollah has traded near-daily fire with Israeli forces since the Palestinian militant group's October 7 attack on Israel triggered war in Gaza, with violence intensifying in recent weeks.

- 'Tanker convoy' -

On Monday, Hezbollah said it had downed an Israeli Hermes drone over Lebanon.

The Israeli military said that overnight its "fighter jets struck a military complex of... the logistical reinforcement unit of the Hezbollah terrorist organisation".

"The unit is used to smuggle weapons to and from Lebanon," it said in a statement, adding that it had hit two targets in eastern Lebanon's Baalbek area, a Hezbollah stronghold located in the Bekaa valley.

The Israeli army said it also struck in southern Lebanon overnight, adding that the strikes came after one of its drones was shot down on Monday.

Rami Abdel Rahman, head of the Britain-based war monitor the Syrian Observatory for Human Rights, said an "Israeli strike" targeted "a convoy of tankers entering Lebanon on the border with Syria".

He said at least three Syrians working with Hezbollah were killed, adding that the Lebanese militant group controls both sides of the frontier in the area where the strike hit.

Hezbollah for years has fought on the side of President Bashar al-Assad in Syria's civil war, which erupted in 2011.

More than eight months of cross-border violence has killed at least 463 people in Lebanon, mostly fighters but also including almost 90 civilians, according to an AFP count.

On the Israeli side of the border, at least 15 soldiers and 11 civilians have been killed, according to the army.