Saturday’s attack came days after Israel reinforced its offensive against Hamas, a Hezbollah ally, in Gaza.
The Israeli military said it had intercepted three rockets in the northern Israeli town of Metula, and there were no reports of casualties.
The Lebanese military said it had dismantled “three primitive rocket launchers” in the south, and the country’s defence minister said an investigation had been launched into the attack.
Hezbollah, the main armed group active in Lebanon, said it had not carried out the attack, and that it remained committed to the ceasefire that ended 14 months of conflict in Lebanon.
This is the worst violence since the fragile ceasefire, brokered by the US and France, came into effect.
Under the terms of the deal, the Lebanese military would deploy thousands of additional soldiers to the south of the country to prevent armed groups from attacking Israel.
Hezbollah was required to remove its fighters and weapons, while the Israeli military would withdrawal from positions occupied in the war.
But Israel has carried out nearly daily air strikes on what it describes as Hezbollah targets, and has indicated that attacks will continue to prevent the group from rearming.
The Israeli military is still occupying five locations in southern Lebanon, in what the Lebanese government says is a violation of the country’s sovereignty and a breach of the deal.
Israel says the Lebanese military has not yet fully deployed to those areas, and that it needs to remain at those points to guarantee the security of its border communities.
Saturday’s attack on Israel will put even more pressure on the Lebanese government, and probably be used as an example by Israel that the Lebanese army does not have full control of southern areas, where Hezbollah has traditionally had a strong presence and support.
Lebanon’s President Joseph Aoun, who came to power in January, has said only the state should have arms in the country, in what is seen as a reference to Hezbollah’s arsenal.
On Saturday, he condemned “attempts to drag Lebanon into a cycle of violence”, while Prime Minister Nawaf Salam said the escalation carried the “risk of dragging the country into another war”.
The UN peacekeeping force in Lebanon, Unifil, said it was “alarmed by the possible escalation of violence”, urging both Israel and Lebanon to “uphold their commitments”.
Hezbollah was battered in the conflict with Israel: many of its leaders were assassinated, hundreds of fighters killed and much of its arsenal destroyed.
The group faces the huge challenge of providing financial help to its communities affected by the war, and pressure from its opponents to disarm.
Lebanon’s international partners say they will only help the country if the government acts to curb Hezbollah, the most powerful group in Lebanon.
Hezbollah launched its campaign the day after the Hamas attacks on southern Israel on 7 October 2023, saying it was acting in solidarity with Palestinians in the Gaza Strip.
The longstanding conflict escalated and led to an intense Israeli air campaign across Lebanon, and a ground invasion of southern Lebanon.
The offensive killed about 4,000 people in Lebanon – including many civilians – and led to the displacement of more than 1.2 million residents.
Israel’s stated goal in its war against Hezbollah was to allow the return of about 60,000 residents who had been displaced from communities in the country’s north because of the group’s attacks, and to remove it from areas along the border.
