Hezbollah has completed the first phase of a retaliatory attack on Israel with “a large number of missiles” in response to the killing of resistance commander Fuad Shukr at the end of July, Al Jazeera reported.

The Lebanese group said in a statement on Sunday that it fired more than 320 Katyusha rockets at 11 Israeli military bases and barracks, including the Meron base and four sites in the occupied Golan Heights. The response was a hotly anticipated one, weeks in the making against Israel’s targeted killings of senior commanders of Hezbollah and Hamas, mounting concern of regional escalation.

Hezbollah said it targeted military bases to “facilitate the passage of drones” towards their desired targets deep inside Israel. “And the drones have passed as planned.”

“Our military operation for today has been completed and accomplished,” Hezbollah said, Press TV reported.

This comes as Israel launched a series of intense air raids on southern Lebanon early on Sunday in what it said was a “preemptive” attack launched when Hezbollah’s preparation to attack northern Israel was detected.

“Most of the Israeli strikes on Lebanon were in the border area, up to 5km [3 miles] deep along the 120km [74-mile] border,” said Al Jazeera’s Zeina Khodr, reporting from Lebanese town Marjayoun.

“The border area is now a military zone. It’s been evacuated … It’s been repeatedly hit by the Israeli army in recent months.”

While Hezbollah and Israel have been exchanging tit-for-tat attacks across the border with some intensity since the start of Israel’s war on Gaza in October, this marks a significant escalation.

A resident of the southern Lebanese town of Zibqin, some 7km (4 miles) from the border, told the Reuters news agency it was the first time he had awakened “to the sound of planes and the loud explosions of rockets – even before the dawn prayer. It felt like the apocalypse.”

Lebanon’s NNA news agency reported one person was critically injured in a drone attack in Qasimia and a later Israeli air attack killed one person in the town of Khiam.

‘Special situation’

Israel’s War Minister Yoav Gallant declared a “special situation” and announced a 48-hour nationwide state of emergency from 6am (03:00 GMT) on Sunday.

Israel’s Ben Gurion airport was temporarily closed in the early hours of the morning, while reports emerged of some injuries in northern Israel. The Israeli army also announced a series of restrictions on civilians in northern Israel and the Golan Heights, including the closure of some beaches.

Israel’s Army Radio, citing defence officials, said the military assessed that Hezbollah had been preparing to fire hundreds of missiles into central Israel in an attack planned for 5am.

About 100 Israeli jets then foiled the missile strikes, beginning their attack half an hour beforehand, the report said, adding that the military assessed the subsequent Hezbollah barrage was “improvised”.

Prime Minister Benjamin Netanyahu said Israel was “determined to do everything possible to defend” itself. “Whoever harms us – we harm him,” he said in a statement.

Following the attacks, Al Jazeera’s Khodr said: “There are reports that this initial wave of attacks in southern Lebanon has now ended, so we’re waiting to hear from the Israeli military to see whether or not they plan to carry out more strikes, which could, in turn, trigger a Hezbollah response and expand this conflict.

“This is, and has been, a very dangerous conflict, even though largely contained, there is a real concern that it could expand and spiral out of control.”

The Israeli military said most of its attacks against Hezbollah were in southern Lebanon for now, but it will strike anywhere where there is a threat.

Global concern that Israel’s war will escalate into an all-out regional conflict multiplied after the assassination last month of Hamas political chief Ismail Haniyeh in Tehran and of Shukr in Beirut, both blamed on Israel.

Israel’s attacks have “the potential to draw the whole region into the full-blown war”, Sami Nader, the director of the Levant Institute for Strategic Affairs, told Al Jazeera.

He said while this signals a “major escalation in terms of scope of operation and intensity”, both Hezbollah and Israel “are trying to avoid full-blown war”.

Israel, he said, is “exhausted” by its war on Gaza, and the Lebanese group does not want to see a war similar to the one that occurred in 2006 as Lebanon is in a “serious economic crisis”.

Meanwhile, the United States said on Sunday it would “keep supporting Israel’s right to defend itself”.

At President Joe Biden’s direction, “senior US officials have been communicating continuously with their Israeli counterparts”, US National Security Council spokesman Sean Savett said in a statement.

Sunday’s attack came as Egypt hosted a new round of talks aimed at ending Israel’s war on Gaza, now in its 11th month. Hezbollah has said it will halt the fighting if there is a ceasefire.

No diplomatic settlement, however, appears to be taking form and “Israel is determined to change rules of engagement” that would allow a return of all Israelis who were evacuated from northern Israel, said Nader.