Israel's military said early on Saturday that about 10 projectiles had crossed from Lebanon into Israeli territory and that "some" had been intercepted. A statement from the military did not identify the projectiles, which it said were detected after sirens sounded in the Upper Galilee area.

There was no immediate confirmation of Nasrallah's fate after Friday's heavy strikes, but a source close to Hezbollah told Reuters he was not reachable. The Lebanese armed group has not made a statement.

The latest escalation has sharply increased fears the conflict could spiral out of control, potentially drawing in Iran and the US.

Lebanese health authorities confirmed six dead and 91 wounded in the initial attack on Friday - the fourth on Beirut's Hezbollah-controlled southern suburbs in a week and the heaviest since a 2006 war.

The toll appeared likely to rise much higher. There was no word on casualties from the later strikes. More than 700 people were killed in strikes over the past week, authorities said.