JERUSALEM — In a development that could heighten tensions between Israel and Iran, guerrillas of the Lebanon-based Shiite Muslim group Hezbollah succeeded Sunday, apparently for the first time, in penetrating Israeli airspace with an unmanned aerial drone.
The Israeli military acknowledged the incursion in a terse statement and said the aircraft had been supplied by Iran.
Hezbollah said in a statement released to news agencies in Beirut that the reconnaissance flight was "a natural response to the Zionist enemy's repeated and permanent violations of Lebanese airspace."
The drone flew as far as the Israeli coastal city of Nahariya, several miles south of the Lebanese border, before being brought back safely to base, Hezbollah said. Israeli media reports, however, cited military sources as saying the craft had crashed into the Mediterranean Sea.
Other than occasional battles, the Israeli-Lebanese frontier has been relatively calm since Israel withdrew troops in May 2000 from southern Lebanon. But Israel continues to regard Hezbollah as a dangerous adversary, primarily because of its ties to Iran and Syria.
Although the unmanned drone carried no weapons system, an Israeli army spokesman, Capt. Jacob Dallal, called the flight "a violation of our sovereignty, which we take very, very seriously."
He said he knew of no other such aerial incursions by Hezbollah, and the group was not previously known to possess any aircraft.
The drone's flight was brief, but nonetheless represented an embarrassment for the Israeli air force, which prides itself on the high-tech surveillance methods used in its round-the-clock vigilance over Israeli airspace.
In the last year, Israel has accused Syria and Iran of providing Hezbollah with sophisticated weaponry, including rockets and missiles able to reach Haifa, a large Israeli coastal city about 20 miles from the Lebanese border.
Israel also has expressed growing alarm in recent months about Iran's nuclear ambitions, and says Iranian aid to Hezbollah underscores the Islamic Republic's hostile intentions.
In its statement, the Israeli army made a thinly veiled threat against Lebanon, suggesting that if it did not rein in Hezbollah, it could pay a price.
"This is further evidence of the lack of control of the Lebanese government of activities carried out from within its territory, something which may cause harm to Lebanon and its citizens," the statement said. "The state of Israel views gravely any infiltration into its sovereign territory from the air, sea or by land, and will act to ensure the security of its citizens."
Israel often has been criticized by the Lebanese government and the United Nations for its own military reconnaissance flights over Lebanon, which frequently draw antiaircraft fire from Hezbollah fighters and the Lebanese army.
In its statement, Hezbollah boasted of its "qualitative new achievement" and promised more such flights over "occupied northern Palestine."