The launch of the aircraft on Saturday appeared to be an attempt by Hezbollah to influence US-brokered negotiations between Israel and Lebanon over their maritime border, an area that is rich in natural gas.
In a statement, the Israeli said the aircraft were spotted early on and did not pose an "imminent threat." Nonetheless, the incident drew a stern warning from Israel's caretaker prime minister, Yair Lapid.
"I stand before you at this moment and say to everyone seeking our demise, from Gaza to Tehran, from the shores of Lebanon to Syria: Don't test us," Lapid said in his first address to the nation since taking office on Friday. "Israel knows how to use its strength against every threat, against every enemy."
Israel earlier this month set up a gas rig in the Karish field, which Israel says lies within part of its internationally recognised economic waters. Lebanon has claimed it is in disputed waters.
Hezbollah issued a short statement, confirming it had launched three unarmed drones toward the disputed maritime issue over the Karish field on a reconnaissance mission. "The mission was accomplished and the message was received," it said.
Israel and Hezbollah are bitter enemies that fought a month-long war in the summer of 2006. Israel considers the Iranian-backed Lebanese group its most serious immediate threat, estimating it has some 150,000 rockets and missiles aimed at Israel.
The US last week said that mediator Amos Hochstein had held conversations with the Lebanese and Israeli sides. "The exchanges were productive and advanced the objective of narrowing differences between the two sides. The United States will remain engaged with parties in the days and weeks ahead," his office said in a statement last week.
The two countries, which have been officially at war since Israel's creation in 1948, both claim some 860 square kilometres of the Mediterranean Sea. Lebanon hopes to exploit offshore gas reserves as it grapples with the worst economic crisis in its modern history.
On Saturday, Lebanese Prime Minister Najib Mikati told reporters that Lebanon received "encouraging information" regarding the border dispute but refused to comment further saying Beirut is waiting for the "written official response to the suggestions by the Lebanese side."
