According to the military, the air force struck 10 targets in the Dahiyeh suburbs of Beirut within about 30 minutes.
Hezbollah said late Wednesday that its new campaign, named ‘Eaten Straw’, was launched in response to Israeli attacks.
The infantry unit had been involved in combat operations in Gaza during Israel’s prolonged offensive in the enclave.
Syria’s armed forces said a military base near the Lebanese border came under artillery attack by the Lebanese militia Hezbollah.
Security sources said the strike killed a senior official from Hamas.
The UN has urgently called for the protection of civilians and warned of growing displacement and humanitarian needs.
The deployed units belong to the border guard and reconnaissance battalions tasked with monitoring border activities and combating smuggling, the ministry added.
The Hezbollah militia in Lebanon early on Monday claimed responsibility for targeting a site south of the city of Haifa belonging to the Israeli military.
The Israeli military has advised residents in southern Lebanon and the Bekaa Valley to evacuate their homes immediately ahead of strikes on Hezbollah militia targets.
The Israel Defence Forces said the wave of strikes hit military infrastructure used by the Iranian-backed group to plan attacks against the Jewish state.
