The attacks, which were widely believed to be carried out by Israel targeting Hezbollah, have hiked fears that the two sides’ simmering conflict could escalate into all-out war.

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.

The Iran-backed Hezbollah blamed Israel for the explosion of thousands of its operatives' pagers and radios in attacks that spanned two days this week. Israel has yet to comment on the attacks.