U.N. peacekeepers in Lebanon urged immediate de-escalation as hostilities rumbled on at the Lebanese-Israeli border on Friday, following Israel's most intense airstrikes in nearly a year of conflict with the Iran-backed Hezbollah.

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.

Secretary of State Antony Blinken traveled to Egypt for fresh talks on an Israel-Hamas cease-fire, as tensions with Hezbollah persist at the Israel-Lebanon border in the wake of the shocking explosions of wireless devices.

It is uncharted territory in the conflict between Israel and the Hezbollah militant group after a deadly string of explosions affecting pagers and other devices in Lebanon reportedly killed several people and injured hundreds.