Israel's military announced Saturday that Hezbollah chief Hassan Nasrallah was killed in an Israeli strike on Beirut the previous night, but there was no confirmation from the Lebanese armed group.
"Hassan Nasrallah is dead," military spokesman Lieutenant Colonel Nadav Shoshani announced on X.
Captain David Avraham, another military spokesman, also confirmed to news agency AFP that the Hezbollah chief had been "eliminated" following strikes Friday on the Lebanese capital.
A source close to the Iran-backed group told AFP on condition of anonymity that contact with Nasrallah had been lost since Friday evening.
Contact with him was lost for two days and he was rumoured to have been killed during Israel's last war with Hezbollah in 2006, the source said, adding that he later re-emerged unscathed.
There has been no official confirmation from Hezbollah about Nasrallah's fate since the Israeli military's announcement.
An Israeli military statement said the strikes also killed Ali Karake, who the statement identified as commander of Hezbollah's southern front, and an unspecified number of other Hezbollah commanders.
"The strike was conducted while Hezbollah's senior chain of command were operating from the headquarters and advancing terrorist activities against the citizens of the State of Israel," the statement said.
"During Hassan Nasrallah's 32-year reign as the Secretary-General of Hezbollah, he was responsible for the murder of many Israeli civilians and soldiers, and the planning and execution of thousands of terrorist activities," the statement conflict.
Hezbollah and Israel have been in conflict since the war in Gaza began on October 7.
Israel dramatically escalated this with a series of explosions targeting pagers used by Hezbollah members earlier this month, and with massive airstrikes that targeted southern Lebanon and the Dahieh area of Beirut beginning on Monday.
At least 700 people have been killed in Lebanon over the past week, with more than 200,000 fleeing their homes in the south of the country.