The Israeli military said dozens of warplanes were striking Hezbollah targets in southern Lebanon late Saturday, as cross-border exchanges intensify amid growing fears of all-out war.
Israel also announced additional security measures for the country's north.
"In the last hour we are attacking widely in southern Lebanon following the identification of Hezbollah's preparations to fire into Israeli territory," military spokesman Rear Admiral Daniel Hagari said in a televised statement shortly after 8pm (1700 GMT).
Earlier in the day the military said it had hit thousands of rocket launcher barrels and other targets belonging to Hezbollah.
The barrages came one day after an Israeli strike on Beirut killed 37 people, according to Lebanese officials, including senior commanders of Hezbollah.
Rescuers in Beirut hunted for people still missing in rubble after the Israeli airstrike targeting Hezbollah commanders.
Hezbollah, a powerful Iran-backed group, said that 16 members including senior leader Ibrahim Aqil and another commander, Ahmed Wahbi, were among those killed 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.
Friday's strike followed sabotage attacks on pagers and two-way radios used by Hezbollah on Tuesday and Wednesday, which killed 39 people. Hezbollah blamed Israel, which has not commented.
Tens of thousands of people have been displaced from both sides of the Israel-Lebanon border.
In a separate statement, the military said it was tightening restrictions on public gatherings in northern Israel.
Smoke billows at the site of an Israeli airstrike on the outskirts of the southern Lebanese village of Zawtar Saturday.
Mourners attend the funeral of members of Hezbollah who were killed in an Israeli strike on Friday, in the southern suburb of Beirut Saturday.
