Smoke was seen rising after an explosion was heard. The Israeli military says it attacked the Beirut area early Monday.
The forces "hit infrastructure belonging to the terrorist organization Hezbollah in Beirut," the military said in a statement.
The fighting in eastern Lebanon is reportedly taking place on the outskirts of the town of Nabi Chit.
Hezbollah says it has detected "around 15" Israeli helicopters coming from the Syrian side of the border into eastern Lebanon.
Two Hezbollah sources previously told AFP that an Israeli helicopter in the area had been shot down by Hezbollah. The incident allegedly took place in the "mountains east of Baalbek." The Israeli military has so far not commented on the incident.
In southern Lebanon, Hezbollah says it is fighting Israeli soldiers who have entered the Lebanese border towns of Odaisseh and Aitaroun.
