The Hezbollah leader, Hassan Nasrallah, did not say how his group would respond to attacks on hand-held devices, which killed dozens when pagers and walkie-talkies exploded.

Israeli Defense Minister Yoav Gallant did say on Wednesday, however, that his country's war with Iran's so-called proxy groups in the region had entered a "new phase," announcing a shift to the north of Israel after 11 months of intense conflict with Hamas in the Gaza Strip.

Israel launched a wave of airstrikes against Hezbollah targets in southern Lebanon, moments before the militant group’s leader said two days of debilitating attacks on its members amounted to a declaration of war.