A source close to Lebanon's Hezbollah said an Israeli strike on south Beirut killed Ibrahim Kobeissi, who Israel said was one of the Iran-backed group's top commanders, with authorities reporting six dead.
It was the second strike on the Hezbollah stronghold in as many days after Israel launched extensive raids Monday in Lebanon's south and east, killing more than 550 people and sending tensions soaring.
"The Israeli strike on Beirut's southern suburbs killed Hezbollah military commander Ibrahim Kobeissi," the source told AFP, requesting anonymity to discuss sensitive matters.
Earlier, Israel's army said it "eliminated Ibrahim Mohammed Kobeissi, the commander of the missile and rocket network of the Hezbollah terrorist organisation".
The military said Kobeissi commanded several rocket units, including a precision-guided missile unit, and was hit along with other commanders of Hezbollah's missiles and rockets force.
"Kobeissi was an important source of knowledge in the field of missiles and had close ties with senior Hezbollah military leaders," it said.
He had joined Hezbollah in the 1980s and held several military positions, including command of the Badr unit, one of Hezbollah's three zones of operations in Lebanon's south, the military added.
The "Israeli enemy raid on Ghobeiri in Beirut's southern suburbs killed six people and injured 15," Lebanon's health ministry said in a statement.
An AFP photographer at the site of the strike said the attack had destroyed two floors of a building located in a densely packed residential area, also damaging dozens of nearby cars and motorbikes.
A crane was brought in to evacuate residents stranded in their apartments in nearby damaged buildings, the photographer said, with other cranes moving vehicles and removing rubble.
Hezbollah security cordoned off the site of the strike while rescuers looked for survivors amid the rubble of damaged buildings, water tanks and torn electric wires.
On Monday, Israel said it had launched another "targeted strike" on Beirut.
Hezbollah said Ali Karake, its third-in-command, was alive and had moved to safety after a source close to the group told AFP the strike had targeted him.
Hezbollah and its arch-foe Israel have been exchanging near-daily cross-border fire since the Gaza war erupted last October.
But on Monday, Israel launched devastating strikes that resulted in the deadliest single-day toll since the end of Lebanon's 1975-1990 civil war.
The attacks came after coordinated explosions of communication devices killed 39 people and wounded thousands on Tuesday and Wednesday last week.
Those were followed by a deadly strike on Friday on south Beirut, with leading Hezbollah commander Ibrahim Aqil among the dead.
