Israeli security officials are reportedly examining the possibility that a drone shot down deep in Israeli territory on Saturday may have been despatched in a Hezbollah-Iranian operation and may have been sent to surveil the Dimona nuclear site.

The army was still examining the remains of the downed unmanned aerial vehicle (UAV) Saturday night and had released no official information about its investigation. But Israeli media reports suggest officials fear the drone may have been part of a larger operation to spy on strategic sites inside the country.

According to the Hebrew website Ynet, defense officials are examining the possibility that the drone was sent as part of an Iranian-backed operation meant to photograph the Dimona nuclear installation, home to Israel’s nuclear weapon program according to foreign media reports.

Israel has been seeking to encourage the international community to act with more urgency to thwart Iran’s nuclear drive, and has indicated that it might seek to strike at Iran’s nuclear facilities if all else fails. Iranian officials have vowed that any Israeli attack would prompt a counter-strike that would be catastrophic for Israel.

Army vehicles and helicopters are seen in an open area as they search for the remains of a drone in the Negev Saturday. (photo credit: AP/Yehuda Lachiani)

Army vehicles and helicopters are seen in an open area as they search for the remains of a drone in the Negev Saturday. (photo credit: AP/Yehuda Lachiani)

The drone reportedly originated in Lebanon, but took a circuitous route through the Mediterranean sea and around Israeli territorial waters before turning east and flying over Gaza and into Israel, according to reports on Israel Radio and in Maariv.

That route may have been designed to conceal the origin of the  unmanned aircraft, or to evade Israeli detection. Nonetheless, the army reported that it began tracking the plane while it was still over the sea and shot it down over the Yatir forest, on the edge of the southern Negev desert, after it reached an unpopulated area.

The drone had spent about 20 minutes in Israeli air space, an Israeli military official said on condition of anonymity in line with protocol.

Israel media reported that the aircraft was not carrying explosives and could have been a surveillance drone.

Defense Minister Ehud Barak said in a statement that Israel views “this incident of attempting to enter Israeli airspace very severely and we will consider our response later,” while Prime Minister Benjamin Netanyahu vowed that Israel “will continue to defend our borders in the sea, on the land and in the air for the security of the citizens of Israel.”

It’s not the first time that Israel has shot down a drone in its airspace, although such cases are very rare.

Hezbollah sent a few aircraft over Israel over the past decade but without much success. In the 2006 war, the militant group launched an Iranian-made drone capable of carrying explosives into Israel that was shot down. Another drone two years earlier crashed in the Mediterranean.

The army has apparently added intercepting drones to its training for a possible war with Hezbollah, according to a report in Haaretz.

It’s not clear if the drone was operating by preprogrammed instruction or if it was controlled remotely from Lebanon. If remote-controlled, the drone would show a level of sophistication the IDF has not believed Hezbollah possesses, according to a report in Ynet.

Hezbollah and Iran both refrained from immediately commenting on the drone’s downing. However a retired Lebanese general told Iran’s state-run Press-TV that the drone could have been an American aircraft accidentally shot down by Israel.

“It is impossible [that it] came from Lebanon and the only possibility [if it came] from the sea is that it was from an American aircraft carrier or from Saudi Arabia, [which also has] American bases,” Maj. Gen. Hisham Jaber told the news outlet.

In an address in August, Hezbollah’s leader Sheikh Hassan Nasrallah said his group has a list of Israeli targets that it can hit with very few rockets. He said a small number of precisely fired missiles on carefully selected targets could “transform the lives of millions of Zionists in occupied Palestine to a real hell,” and spoke of tens of thousands of Israeli fatalities.

Late last month, a top-ranking Iranian general said Israeli preparations to attack Iran could trigger a pre-emptive attack and “World War III.” Brigadier General Amir Ali Hajizadeh, who heads the missile command for the Revolutionary Guards, told the country’s Arabic-language Al-Aram that as things stood now Iran would not attack, but that could change.

“In circumstances in which [the Israelis] have prepared everything for an attack, it is possible that we will make a pre-emptive attack,” he said. “[Israel] cannot imagine our response — and it will sustain heavy damage and that will be a prelude to its obliteration.”

The Associated Press contributed to this report.