A single drone, which evaded Israel’s vaunted aerial defense system, slammed into a mess hall at a military training camp deep inside Israel, killing four soldiers and wounding dozens of others.

The drone attack was one of the deadliest attacks by the Iran-backed militant group since Israel launched its ground invasion of Lebanon nearly two weeks ago.

Hezbollah’s deadly attack against an army base deep inside Israeli territory presents a major headache for Israel as it continues to struggle to defuse the threat posed by the group.