A fresh wave of air raids hit Beirut's southern suburbs in the early hours of Saturday as Israel stepped up attacks on Hezbollah, after a massive strike on the Iran-backed movement's command center that apparently targeted leader Hassan Nasrallah.

Witnesses heard more than 20 separate airstrikes before dawn on Saturday. Abandoning their homes in the southern suburbs, thousands of Lebanese congregated in squares, parks and sidewalks in downtown Beirut and seaside areas.

Heavy strikes shook southern Beirut on Friday too. There was no immediate confirmation of Nasrallah's fate. But a source close to Hezbollah said he was not reachable, and the Lebanese armed group had not made a statement.