Israel said it had shot down three drones headed from Lebanon toward one of its Mediterranean gas rigs on Saturday and accused the Iranian-backed Hezbollah party of launching them.
There was no immediate response from Lebanon to the Israeli allegation, which came amid tensions between the countries over the location of the Karish rig and long-standing but so-far fruitless US-mediated efforts to agree on a maritime border.
The Israeli military said its forces had intercepted "three hostile UAVs which approached the airspace over Israel's economic waters".
An Israeli security source said the drones had been unarmed, although this was not immediately confirmed by the military.
Defense Minister Benny Gantz accused Hezbollah of being behind the launch, saying in a statement that it was "preventing the state of Lebanon from reaching an agreement regarding maritime borders, which are critical to the economy and prosperity of the Lebanese nation".
Saturday's interceptions were the first time an air defense system mounted on an Israeli naval ship had downed an incoming target, the military said.