The Israeli military said it had targeted Hezbollah's central headquarters in Beirut's southern suburbs on Friday in an attack that shook the Lebanese capital and sent thick clouds of smoke over the city.
The news outlet Axios cited an Israeli source as saying Hezbollah leader Sayyed Hassan Nasrallah was the target of the strike and that the Israeli military was checking if he was hit.
Hezbollah's al-Manar television reported that four buildings were destroyed and there were many casualties in the multiple strikes, which marked a major escalation of Israel's conflict with the group.
The Israeli military said it had carried out a "precise strike" on Hezbollah's headquarters which it said were embedded under residential buildings.
Israel has struck the Hezbollah-controlled southern suburbs of Beirut, known as Dahiyeh, four times over the last week, killing at least three senior Hezbollah military commanders.
But Friday's attack was far more powerful, with multiple blasts shaking windows across the city, recalling Israeli airstrikes during the war it fought with Hezbollah in 2006.
The strikes hit Beirut shortly after Israeli Prime Minister Benjamin Netanyahu vowed to continue Israel's attacks on Iranian-backed fighters in Lebanon in a closely watched United Nations speech, as hopes faded for a ceasefire.
Hamas is seeking guarantees that a new US ceasefire proposal for Gaza would lead to the war's end, a source close to the group said on Thursday, as medics said Israeli strikes across the territory had killed scores more people.
The Pentagon said on Wednesday that US strikes 10 days ago had degraded Iran's nuclear programme by up to two years, suggesting the US military operation likely achieved its goals despite a far more cautious initial assessment that leaked to the public.
Hundreds of firefighters battled a blaze Thursday on Crete island, which burnt swathes of forest and olive groves and forced the evacuation of over 1,000 people, officials said, underscoring the region's vulnerability to destructive wildfires.
Five people were injured, including a seven-year-old boy and a nine-year-old girl, in a Russian attack on the southern Ukraine port of Odesa overnight, Ukrainian authorities said on Thursday.