"Enemy aircraft launched three strikes on (Beirut's) southern suburbs," the official National News Agency (NNA) reported.

A source close to the group told AFP the strike "targeted a building housing Hezbollah's media relations office," which had already been "evacuated".

This week, Israel announced that its troops had started "ground raids" into parts of southern Lebanon, a stronghold of Hezbollah, after days of heavy bombardment of areas across the country where the militant group holds sway.

After nearly a year of low-intensity cross-border fighting, Israel has shifted the focus of its operation from Gaza to Lebanon, where heavy bombing has killed more than 1,000 people and forced hundreds of thousands to flee.

Last week, Israel killed Hezbollah leader Hassan Nasrallah in the group's southern Beirut bastion, a densely packed residential area before residents fled the violence.