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.

Lebanese health authorities reported that at least three people were killed and more than a dozen others wounded in an Israeli strike on the capital Beirut on Friday, the first such Israeli attack on the Lebanese capital in months.

The strikes came hours after Hezbollah’s leader vowed that “retribution will come” to Israel for the explosions of Hezbollah members’ hand-held devices. At least 37 people were killed and more than 2,900 others injured in those explosions on Tuesday and yesterday. Here’s the latest.