An Israeli air strike targeted a senior Hezbollah commander in Beirut's southern suburbs late on Tuesday.
The Israeli military said it was in retaliation for a cross-border rocket attack three days before that killed 12 children and teenagers.
A loud blast was heard and a plume of smoke could be seen rising above the southern suburbs - a stronghold of the armed group Hezbollah - at around 7:40 pm (1640 GMT), a Reuters witness said.
A senior Lebanese security source said a senior Hezbollah commander had been the target of the air strike and his fate remained unclear.
Lebanon's state-run national news agency said an Israeli air strike had targeted the area around Hezbollah's Shura Council in the Haret Hreik neighbourhood of the capital.
Beirut has been on edge for days ahead of an anticipated Israeli attack in reprisal for the rocket strike on the Israeli-occupied Golan Heights on Saturday that killed the 12 youngsters in a football field in a Druze village.
Hezbollah has denied involvement in that attack.
As diplomats sought to contain the fallout, US Defence Secretary Lloyd Austin said he did not believe a fight was inevitable between Hezbollah and Israel, though he remained concerned about the potential for escalation.
Foreign ministers from European countries, Australia and Britain on Friday jointly condemned Israel's plans to construct a settlement east of Jerusalem.
Famine has struck an area of Gaza and will likely spread over the next month, a global hunger monitor determined on Friday, an assessment that will escalate pressure on Israel to allow more humanitarian aid into the war-torn Palestinian enclave.
North Korean leader Kim Jong Un lauded his country's "heroic" troops who fought for Russia in the war against Ukraine, in a ceremony where he decorated returning soldiers and consoled children of the bereaved with hugs, state media said on Friday.
Former Sri Lankan President Ranil Wickremesinghe, who led the country during a devastating 2019-2024 economic crisis, was arrested and appeared in court on Friday over allegations he misused state funds while in office, police said.
The Arab League has strongly condemned the settlement plan approved by the Israeli government in the area known as E1 east of Jerusalem, stressing that it threatens the territorial continuity of Palestine.