The heavy exchanges of fire came despite an immediate Israel-Hezbollah ceasefire call from top EU diplomat Josep Borrell while on a visit to Lebanon Sunday.
A series of Israeli airstrikes across Lebanon claimed dozens of lives, including 29 fatalities in a devastating attack that flattened a multi-story residential building in the densely populated Basta area of central Beirut.
The 10,000-strong multi-national UNIFIL mission is monitoring hostilities along the demarcation line with Israel, an area hit by fierce clashes between the Iran-backed Lebanese Hezbollah militia and Israeli forces.
The Iran-backed group has been severely weakened after two months of increased Israeli sabotage, air strikes and ground incursions in southern Lebanon.