ISRAEL launched a series of airstrikes in southern Lebanon on Sunday in what it said was a pre-emptive strike against the Hezbollah militant group.

The move could threaten to trigger a broader region-wide war which could torpedo efforts to forge a ceasefire in Gaza.

The Israeli army said Hezbollah was planning to launch a heavy barrage of rockets and missiles towards Israel with the Iranian-backed group promising for months to retaliate for Israel’s assassination of a top commander last month.

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Air raid sirens were reported throughout northern Israel, and Israel’s Ben-Gurion International Airport began diverting incoming flights and delaying takeoffs.

Soon afterwards, Hezbollah announced it had launched an attack on Israel with a “large number of drones” as an initial response to the killing of Fouad Shukur, a top commander with the group, in a strike in Beirut’s southern suburbs last month.

Hezbollah said the attack was targeting “a qualitative Israeli military target that will be announced later” as well as “targeting a number of enemy sites and barracks and Iron Dome platforms”.

The attack came as Egypt hosts a new round of talks aimed at ending Israel’s bombardment of Gaza - which has killed more than 40,000 Palestinians - now in its 11th month. Hezbollah has said it will halt the fighting if there is a ceasefire.

Last week, Israel’s defence minister said he was moving more troops towards the Lebanese border in anticipation of possible fighting with the Iranian-backed group.

Israel’s military spokesman, rear admiral Daniel Hagari, said: ”In a self-defence act to remove these threats, the [Israeli military] is striking terror targets in Lebanon, from which Hezbollah was planning to launch their attacks on Israeli civilians.”

“We can see that Hezbollah is preparing to launch an extensive attack on Israel while endangering the Lebanese civilians,” he added, without providing details.

“We warn the civilians located in the areas where Hezbollah is operating to move out of harm’s way immediately for their own safety.”

Lebanese media reported strikes in the country’s south without immediately providing more details. Social media footage showed what appeared to be strikes in southern Lebanon.

Israeli media cited the Israel Airports Authority for news of the flight cancellations. Flight-tracking data showed at least two El Al flights swinging far south and diverting after the announcement.

Hezbollah began attacking Israel almost immediately after the October 7 attacks into Israel by Hamas.

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Israel and Hezbollah have been exchanging fire nearly daily, displacing tens of thousands of people on both sides of the border and raising fears that the fighting could escalate into all-out war.

But until Sunday, both sides have been careful to avoid a broader conflagration.

Hezbollah is considered much more powerful than its ally, Hamas, with an estimated arsenal of arsenal of 150,000 rockets and missiles, including precision-guided missiles.

In recent months the group has also stepped up its use of drones, against which Israel is less well-equipped to defend.

(Image: Ohad Zwigenberg/AP)

Israeli prime minister Benjamin Netanyahu’s (above) office said he and his defence minister, Yoav Gallant, were managing the latest operation from military headquarters in Tel Aviv.

Gallant declared a “special situation on the home front” and Netanyahu’s Security Cabinet was set to meet later Sunday morning.

It comes as the chief prosecutor of the International Criminal Court urged judges to "urgently" rule on the request for arrest warrants for Netanyahu and Gallant as well as senior Hamas figures.