Israel says one of its fighter jets has shot down an unmanned aircraft sent from Lebanon into Israeli airspace.
A missile brought down the drone about five miles (8km) west of the northern Israeli port of Haifa around 14:00 (11:00 GMT), officials said.
Reports suggest the drone could have been sent by Lebanese militant group Hezbollah, which fought a month-long war against Israel in 2006.
It is the second time in seven months Israel has downed a drone from Lebanon.
Last October, the Israeli air force shot down an unmanned aircraft over the south of the country.
Israeli Prime Minister Benjamin Netanyahu condemned the incident as an “extremely grave” attempt to breach Israel’s borders.
“We will continue to do whatever it takes to protect the security of Israel’s citizens,” he said.
Mr Netanyahu was on his way to the north of Israel in a helicopter when the incident happened. His aircraft landed briefly until the Lebanese plane was shot down.
He recently warned that Hezbollah might try to take advantage of the instability in neighbouring Syria.
Israel says the latest aircraft was detected and monitored while still over Lebanon, and it was shot down by an air-to-air missile fired from an Israeli fighter jet.
“UAVs [unmanned aerial vehicles] pose a serious threat to the state of Israel’s security,” said an IDF report on the incident. “The IDF will not tolerate any attempt to violate Israel’s sovereignty or harm its security.”