Authorities in Israel say they have shot down three Hezbollah drones heading towards one of its gas rigs in a disputed area of the Mediterranean.
Military officials say the drones were launched from Lebanon and were shot down by a combination of fighter jets and ship-mounted missiles.
Hezbollah confirmed it had launched the drones in a short statement.
Tensions have mounted between Israel and Lebanon over ownership of the Karish gas field.
US energy envoy Amos Hochstein is mediating between the two countries to settle the longstanding dispute. Israel says the field lies within its UN-recognised exclusive economic zone, but Lebanon has also laid claim to parts of it.
Hezbollah said it had targeted the rig as part of a reconnaissance flight.
"The mission was accomplished and the message was received," the statement said.
Last week, the group's leader, Hassan Nasrallah, threatened to use force to prevent Israel from operating the rig.
Israeli Defence Minister Benny Gantz said the Islamist group 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".
Hezbollah's reported attack comes amid political instability in Israel. On Thursday lawmakers voted to dissolve parliament and call the fifth election in four years.
The vote, which comes after the collapse of former Prime Minster Naftali Bennett's multi-party coalition, offers Benjamin Netanyahu, the right-wing opposition leader, a chance to return to power.