Killing or incapacitating Hezbollah leader Hassan Nasrallah would deal a significant blow to the Iran-backed Lebanese group he has led for 32 years, analysts said on Friday after reports Israel targeted him with a strike.

A source close to Hezbollah said Nasrallah was still alive after the attack on the southern suburbs of Beirut, a Hezbollah stronghold, on Friday evening. A senior Iranian security official said Tehran was checking on Nasrallah's status.

Replacing Nasrallah would be an even bigger challenge now than at any point for years, after a series of recent Israeli attacks that have killed top Hezbollah commanders and raised questions over its internal security.