Lebanon's health ministry said at least 60 people were killed on Monday in Israeli raids on several areas in the eastern Bekaa Valley, most of them in the Baalbek region.
The health ministry said the tolls covered 12 areas in the Bekaa Valley where militant group Hezbollah holds sway. At least two children were among the dead, it said.
At least 58 others were wounded, the health ministry added, noting that the toll was preliminary as rescue efforts were still underway, reports AFP.
Of the 60 killed, at least 16 deaths were recorded in Al-Alaq, west of Baalbek city, according to the health ministry.
Monday's deaths raise the overall toll to more than 1,700 killed in Lebanon since the Israel-Hezbollah war erupted late last month, according to an AFP tally of health ministry figures.
The real number is likely to be higher due to gaps in the data.
Baalbek governor Bachir Khodr decried what he called the "most violent" raids on the area since the start of the conflict.
Baalbek is an impoverished region in the Bekaa Valley that borders Syria.
The heavy strikes there on Monday were not preceded by an evacuation warning.
They came as Israel pounded south Lebanon, including the coastal city of Tyre, according to the official National News Agency.
The Israel-Hezbollah war erupted on September 23 after nearly a year of cross-border fire between the two rivals.
The war has displaced at least 1.3 million people, more than 800,000 inside Lebanon according to the UN's migration agency.
More than half a million people have crossed into Syria, according to Lebanese authorities, most of them Syrians.