Hezbollah launched hundreds of missiles and drones into Israel in retaliation for the assassination of a senior commander in Beirut last month.
The violence on August 25 was one of the largest firefights since the conflict began between Israel and Hezbollah in parallel with the outbreak of Israel's war against the Hamas group in Gaza.
In a statement, the Israeli military said about 100 Israeli jets attacked more than 40 Hezbollah launch sites in southern Lebanon shortly before the force's attack.
Hezbollah also claimed to have launched drones and more than 320 Katyusha missiles toward Israel and attacked 11 military targets. Hezbollah said it had completed the "first phase" of the attack in response to the assassination last month of Fuad Shukr, a senior Israeli commander, in Beirut.
Hezbollhah denied Israel's accusations of pre-emptive strikes but said in a statement that its military operation was successfully completed during the day.
Israeli Prime Minister Benjamin Netanyahu chaired an emergency security cabinet meeting at 7 a.m. local time.
“We are determined to do everything we can to protect the country, bring the people of the North home safely and continue to maintain a simple rule: Whoever harms us - we will harm that person,” Mr. Netanyahu said in a statement.
Foreign Minister Israel Katz said Israel would react to developments on the ground but did not seek a full-scale war.
An Israeli military spokesman said that most Israeli attacks were aimed at targets in southern Lebanon but that the army was ready to strike wherever there was a threat.
Israel declared a state of emergency and flights to and from Ben Gurion airport in Tel Aviv were suspended for about 90 minutes, but airport authorities said normal operations were expected to resume. continues at 7 am.
