The Israeli military says it has shot down an unmanned aircraft several kilometres off the coast of the northern port city of Haifa after it entered Israeli airspace from Lebanon.
"An unmanned aircraft [UAV] was identified approaching the coast of Israel and was successfully intercepted by IAF aircraft five nautical miles off the coast of Haifa at approximately 14:00 [1100 GMT] today," the military said.
Israel's deputy defence minister blamed the drone Lebanese group Hezbollah, which sent a similar drone into Israel last October.
The incident took place as Israeli Prime Minister Netanyahu was flying to attend a ceremony in the Druze village of Julis, some 32 kilometres northeast of Haifa, with the helicopter briefly landing after he received the news.
"I see this attempt to breach our borders as extremely grave," Netanyahu said.
"We will continue to do whatever we must to protect the security of Israel's citizens."
Military spokesman Lieutenant Colonel Peter Lerner told reporters the drone had been identified moving down the Lebanese coast before reaching Israeli airspace.
"A little after 1:00 pm, our aerial defence system identified (a drone) moving from north to south along the coast of Lebanon," he said.
"Aircraft, helicopters and combat airplanes were alerted to the area and after confirmation that it was an unfriendly aircraft, they were approved to shoot it down."
Lerner didn’t say who Israel suspected to be behind the drone, only that the incident was still being investigated.
"We don't know where the aircraft was coming from and where it was actually going," he said, adding that the navy was "searching for the remains of the UAV" as part of the probe.
Tensions with Hezbollah
But Deputy Defence Minister Danny Danon said it was clear that Lebanese group Hezbollah was behind the attack.
"We're talking about another attempt by Hezbollah to send an unmanned drone into Israeli territory," he told Israel's army radio, describing it as "another attempt to destabilise the Middle East."
However, the Lebanese group denied the drone was theirs, saying in a statement on Thursday: "Hezbollah denies that it has sent any surveillance plane towards the occupied Palestinian land."
On October 7, Israeli warplanes shot down an unarmed drone over Israel's southern Negev desert after it entered the country's airspace from the Mediterranean Sea, with Netanyahu blaming Hezbollah.
Several days later, Hezbollah leader Hassan Nasrallah confirmed his group had sent an Iranian-built drone into Israeli airspace and claimed it had overflown sensitive sites in Israel.
He said the drone was "Iranian-built and assembled in Lebanon."
Al Jazeera’s Rula Amin in Beirut said that “the threat of war between Israel and Hezbollah is always there.”
“For many Lebanese it’s even an imminent war, they think that somehow, sooner or later, there will be a war because Israel will try to undermine these capabilities by Hezbollah,” Amin said.
Israel waged a month-long war on Lebanon in 2006 after a Hezbollah cross-border raid. Since that incident, Israeli aircraft has regularly performed overflights into Lebanese territory.