An Israeli airstrike on a car near Syria's capital Damascus on Tuesday killed Salman Jumaa, a senior Hezbollah figure responsible for liaising with the Syrian army, a Lebanese security source told Reuters.
Syria's state news agency had reported the strike on the airport road but did not offer details on casualties.
The Israeli military confirmed in a later statement taking out Jumaa in what it called an intelligence-based strike in Damascus, saying his killing "degrades both Hezbollah's presence in Syria and Hezbollah's ongoing force-building efforts."
Israel rarely acknowledges its strikes in Syria, where it has carried out a years-long air campaign against Iranian military assets and those of its allies, including Hezbollah.
In a rare announcement last month, it said it struck Hezbollah intelligence assets near Damascus.
Israeli Prime Minister Benjamin Netanyahu has warned Syrian President Bashar al-Assad that he was "playing with fire" by allowing Iran to transfer weapons to its allies via Syria.