Israel launched airstrikes on Beirut's southern suburbs and other areas of Lebanon on Saturday, a day after carrying out a massive attack on Hezbollah's headquarters that appeared to be aimed at killing its leader, Sayyed Hassan Nasrallah, Paralel.Az reports citing Reuters.

The fate of Nasrallah, leader of the Iran-backed group for 32 years, remains unclear, with Hezbollah yet to issue any statement on his status.

Reuters journalists heard more than 20 airstrikes in Beirut before dawn on Saturday and more after sunrise. Smoke could be seen rising over the city's Hezbollah-controlled southern suburbs, known as the Dahiyeh.

Thousands of people have fled the area since Friday's attack, congregating in squares, parks and sidewalks in downtown Beirut and seaside areas.

"They want to destroy Dahiyeh, they want to destroy all of us," said Sari, a man in his 30s who gave only his first name, referring to the suburb he had fled after an Israeli evacuation order. Nearby, the newly displaced in Beirut's Martyrs Square rolled mats onto the ground to try to sleep.

The Israeli military said a missile fired at central Israel on Saturday had struck an open area. Earlier, the military said about 10 projectiles had crossed from Lebanon into Israeli territory and that some had been intercepted.

The Israeli military also said it was striking Hezbollah targets in the Bekaa Valley, a region of eastern Lebanon at the Syrian border that it has pounded over the last week.

Israel's five hours of continuous strikes on Beirut early on Saturday followed Friday's attack, by far the most powerful by Israel on the city during the conflict with Hezbollah that has played out in parallel to the Gaza war for nearly a year.

The escalation has sharply increased fears the conflict could spiral out of control, potentially drawing in Iran, Hezbollah's principal backer, as well as the United States.

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.

Israel has not said whether it tried to hit Nasrallah, but a senior Israeli official said top Hezbollah commanders were targeted.

"I think it's too early to say... Sometimes they hide the fact when we succeed," the Israeli official told reporters when asked if the strike on Friday had killed Nasrallah.

Earlier, a source close to Hezbollah told Reuters that Nasrallah was alive. Iran's Tasnim news agency also reported he was safe. A senior Iranian security official told Reuters that Tehran was checking his status.

The Israeli military said in a statement that it had killed the commander of Hezbollah's missile unit, Muhammad Ali Ismail, and his deputy Hossein Ahmed Ismail.

Israel's attacks in Lebanon have widened to new areas this week. On Saturday, an airstrike hit the Lebanese mountain town of Bhamdoun, southeast of Beirut, Lebanese lawmaker for the area Mark Daou told Reuters.

The mayor of Bhamdoun, Walid Khayrallah, told Reuters the strike hit a large empty lot and did not cause any casualties.