The strike on Hezbollah’s stronghold in Lebanon's capital is a major escalation adding to fears of an all-out war.

Iran's U.N. envoy warned the country had the "right to take all necessary measures to respond to this egregious violation."

Israel’s operation against Hezbollah members in Lebanon and Syria through booby-trapped pagers and walkie-talkies was years in the making, and its use now ramped up a high-risk campaign aimed at deeply disrupting the group.