Israel’s killing of Hezbollah’s leader, Hassan Nasrallah, was a stunning escalation of the country’s campaign against the Iran-backed group.

Israel bombed the center of Beirut for the first time in almost a year of hostilities with Lebanon’s Hezbollah, as the military steps up air assaults following the killing of the Iran-backed group’s chief last week.

The carpet-bombing, which leveled an entire residential block, sends Israel’s war on Lebanon into uncharted territory.