Lebanese official media said separate Israeli strikes Tuesday on south Lebanon killed five people including three Syrian children, with Hezbollah announcing rocket fire at Israel in retaliation.

"Three Syrian children" were killed "in an enemy raid that targeted farmland in the village of Umm Toot", the National News Agency (NNA) said.

It also said an "enemy" drone strike had targeted a motorcycle on the Kfar Tebnit road elsewhere in south Lebanon, killing two Syrians.

A Lebanese security source, requesting anonymity as they were not authorised to speak to the media, told AFP that the two Syrians were "civilians" who worked nearby and had been swimming in the area.

The NNA said "eyewitnesses reported that the motorbike was carrying two people and that when a number of citizens tried to approach the bike... it was subjected to a second strike".

Hezbollah said it launched "dozens of Katyusha rockets" at northern Israel's Kiryat Shmona "in response to the Israeli enemy attacks" on south Lebanon, "particularly Kfar Tebnit and "the death of two civilians".

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 Israeli army said that "approximately 40 projectiles were identified crossing from Lebanon into Israeli territory, some of which were intercepted. No injuries were reported."

The statement also said the air force "struck a launcher in the area of Blat that was identified firing projectiles toward the Kiryat Shmona area", as well as "a Hezbollah terrorist cell" in the Yarin area, which is close to Umm Toot.

In Lebanon, the cross-border violence since October has killed 511 people, mostly fighters but also including at least 104 civilians, according to an AFP tally.

On the Israeli side, 17 soldiers and 13 civilians have been killed, according to the authorities.

The violence, largely restricted to the border area, has raised fears of all-out conflict between the foes, who last went to war in the summer of 2006.