Israel and Lebanon have exchanged heavy fire, with Israeli warplanes carrying out the most intense bombardment in almost a year of war across Lebanon's south, while Hezbollah claimed rocket attacks on military targets in Israel's north.
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 and into Sunday as multiple rockets and missiles were fired from Lebanon and Iraq, most of which were intercepted by Israeli aerial defence systems, the military said.
Israeli media reported a number of buildings were hit directly or by falling missile debris, and ambulance services said they treated some lightly injured people. No serious casualties were reported.
An Israeli strike targeted Hezbollah commanders in the Lebanese capital Beirut. (AP PHOTO)
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.
Iran-backed Iraqi militants in a statement also claimed an explosive drone attack on Israel early on Sunday.
The escalating attacks come less than 48 hours after an Israeli airstrike targeting Hezbollah commanders killed at least 37 people in a suburb of the Lebanese capital, according to authorities.
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-storey 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 Lebanon's health ministry.
Friday's strike sharply escalated the conflict and inflicted another blow on Hezbollah after two days of attacks 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 3000 injured. Israel has neither confirmed nor denied involvement.
In what it said was the initial retaliation for the attacks with the exploding devices, Hezbollah on Sunday posted on its Telegram channel that it had launched rockets at Israeli military-industry facilities.
Israel quickly responded, striking Hezbollah targets in Lebanon, the military said in a statement.
Hezbollah has said it would keep fighting until Israel agrees to a ceasefire with Hamas in Gaza. (AP PHOTO)
US national security adviser Jake Sullivan said he was worried about escalation but that the Israeli killing of a top Hezbollah leader brought justice to the group, which Washington designates a terrorist organisation.
"While the risk of escalation is real, we actually believe there is also a distinct avenue to getting to a cessation of hostilities and a durable solution that makes people on both sides of the border feel secure," Sullivan told reporters.
Lebanese Prime Minister Najib Mikati cancelled a planned trip to the UN General Assembly in New York.
Hezbollah has said it would keep fighting Israel until it agrees to a ceasefire in its war against Hamas in the Palestinian enclave of Gaza, triggered by a Hamas-led rampage in southern Israel on October 7.
US officials say that is unlikely anytime soon. Israel wants Hezbollah to cease fire and withdraw forces from the border region, adhering to a UN resolution signed with Israel in 2006, irrespective of any Gaza deal.
with AP