By Timour Azhari and Miro Maman
BEIRUT/KIRYAT BIALIK, Israel (Reuters) -Israel and Hezbollah exchanged heavy fire into Sunday, with Israeli warplanes carrying out the most intense bombardment in almost a year of war across Lebanon's south and Hezbollah firing rockets deep into northern Israel.
The Israeli military said it struck around 290 targets on Saturday, including thousands of Hezbollah rocket launcher barrels, and said it would continue to strike targets of the Iran-backed movement.
Israel closed schools and restricted gatherings in many northern areas of the country and the Israeli-occupied Golan Heights early on Sunday.
Sirens sounded all night as multiple rockets and missiles were fired from Lebanon and Iraq, most of which were intercepted by Israeli aerial defence systems, the military said.
Several buildings were struck, including a house badly damaged near the Israeli city of Haifa. Rescue teams treated wounded but there were no reports of fatalities as residents had been instructed to stay near bomb shelters and safe rooms.
Hezbollah said it targeted the Israeli Ramat David Airbase with dozens of missiles in response to "repeated Israeli attacks on Lebanon", the group posted on its Telegram channel early on Sunday.
The successive barrages of rocket attacks launched by Hezbollah at Ramat David are the deepest strikes it has claimed since hostilities began.
The conflict - sharply escalated over the past week - has been waged since Hezbollah opened a second front against Israel after Israel went to war with Hamas in the Palestinian enclave of Gaza, triggered by the Hamas-led rampage in southern Israel on Oct. 7.
Iran-backed Iraqi militants in a statement also claimed an explosive drone attack on Israel early on Sunday.
The U.N. special coordinator in Lebanon, Jeanine Hennis-Plasscharet, said in a post on X that "with the region on the brink of an imminent catastrophe, it cannot be overstated enough: there is NO military solution that will make either side safer”.
ESCALATING ATTACKS
The escalating attacks come less than 48 hours after an Israeli airstrike targeting Hezbollah commanders in a suburb of the Lebanese capital. The death toll from that strike rose to 45, the Lebanese health ministry said on Sunday.
Hezbollah, a powerful Iran-backed group, said 16 members including senior leader Ibrahim Aqil and another commander, Ahmed Wahbi, were among those killed on Friday in the deadliest strike in nearly a year of conflict with Israel.
Israel's army said it hit an underground gathering of Aqil and leaders of Hezbollah's elite Radwan forces, and had almost completely dismantled its military chain of command.
The attack levelled a multi-story residential building in the crowded suburb and damaged a nursery next door, a security source said. Three children and seven women were among those killed, according to the health ministry.
Friday's strike inflicted another blow on Hezbollah after two days of attacks last week, in which pagers and walkie-talkies used by its members exploded.
The death toll in those attacks, widely believed to have been carried out by Israel, has risen to 39 with more than 3,000 injured. Israel has neither confirmed nor denied involvement.
In what it said was the initial retaliation for the attacks with the exploding devices, Hezbollah posted on its Telegram channel on Sunday that it had launched rockets at Israeli military-industry facilities.
Israel quickly responded, striking Hezbollah targets in Lebanon, the military said in a statement.
ISRAEL BRACES FOR RETALIATION
Hezbollah says it will keep fighting Israel until it agrees to a ceasefire in Gaza.
U.S. officials say that is unlikely anytime soon. Israel wants Hezbollah to cease fire and withdraw forces from the border region, adhering to a U.N. resolution signed with Israel in 2006, irrespective of any Gaza deal.
The Israeli military restricted gatherings and raised the alert level for residents of northern communities. The alert went as far south as the coastal city of Haifa, signalling Israel thought Hezbollah could strike deeper than it had since the war with Hamas began.
In southern Lebanon on Saturday, people described huge explosions that lit up the night sky and shook the ground as Israel carried out its latest strikes.
Israeli Defence Minister Yoav Gallant, who said last week Israel was launching a new phase of war on the northern border, posted on X: "The sequence of actions in the new phase will continue until our goal is achieved: the safe return of the residents of the north to their homes."
Tens of thousands of people have left their homes on both sides of the Israel-Lebanon border since Hezbollah began firing rockets at Israel in October in sympathy with Palestinians in Gaza.
A communique from a U.S. summit hosted by President Joe Biden with the leaders of Japan, India and Australia stressed the need to prevent the Gaza war "from escalating and spilling over in the region" but did not specifically mention the Israel-Hezbollah conflict.
With at least 70 people killed in Lebanon over the past week, the conflict toll in the country since October has surpassed 740 during the worst Israel-Hezbollah flare-up since a 2006 war.