Israeli sources claim that Hezbollah Secretary General Hassan Nasrallah was at the site of the airstrike and is unlikely to have survived.
The Israeli army believes that the military operation was successful, and Nasrallah was killed.
Amos Yadlin, Israel's former intelligence chief, said the Israeli strike would not have happened without complete confidence and that the Hezbollah leader was in the target area.
"My sources are firm; Nasrallah is no longer with us," he said.
