Israel said it pounded Lebanon's Hezbollah, just hours after the group's leader vowed retribution for deadly explosions that targeted its communication devices, killing 37 people and wounding thousands.

Israel warned residents in the north to stay inside or remain near bomb shelters Thursday after the Israeli Air Force struck Hezbollah military targets inside Lebanon.

The attacks offer a rare window into the inner-workings of Hezbollah — an organization that is notoriously secretive and deeply embedded in Lebanese society.