WASHINGTON (AP) - An Israeli airstrike against Syria was targeting a shipment of advanced missiles believed to be bound for the Lebanese militant group Hezbollah, Israeli officials confirmed Saturday.
It was the second Israeli strike this year against Syria and the latest salvo in its long-running effort to disrupt Hezbollah's quest to build an arsenal capable of defending against Israel's air force and spreading destruction inside the Jewish state.
The strike comes as the U.S. considers how to respond to indications that the Syrian regime may have used chemical weapons in its bloody civil war. President Barack Obama has described the use of such weapons as a "red line," and the administration is weighing its options - including possible military action.
Israeli Prime Minister Benjamin Netanyahu has repeatedly warned in recent weeks that Israel would be prepared to take military action if chemical weapons or other arms that would upset the balance of power with Hezbollah were to reach the Islamic militant group.
The Israeli officials said the attack took place early Friday and was aimed at sophisticated "game-changing" weapons, but not chemical arms. One official said the target was a shipment of advanced, long-range ground-to-ground missiles but was not more specific.
They did not say where the attack took place, or whether the air force carried out the strike from Lebanese or Syrian airspace.
The Israeli officials spoke on condition of anonymity because they were not authorized to disclose information about a secret military operation to the media.
U.S. officials had earlier confirmed the airstrike but said only that it appeared to have hit a warehouse.
Calls to the Israeli military and foreign and defense ministries were not immediately answered.
Syria's assistant information minister, Khalaf Muftah, told Hezbollah's Manar TV that he has "no information about an aggression that was staged," and said reports of an Israeli air raid "come in the framework of psychological war in preparation of an aggression against Syria."
Hezbollah declined comment.
Israel has cast a wary eye on Syria's civil war, which has on several occasions spilled over into Israel as well as Turkey, Lebanon and Iraq. The Jewish state is particularly worried about President Bashar Assad regime's stockpile of chemical weapons being transferred to Hezbollah or falling into the hands of Islamic extremists fighting in the rebel ranks.
Concerns about Syria's chemical weapons have spiked in recent weeks amid growing indications that the Assad regime may have used them against the uprising at home.
The U.S. has said intelligence indicates the Syrian government likely has used the deadly nerve agent sarin on at least two occasions, echoing earlier assessments from allies Britain, France and Israel. Obama has characterized the use of chemical weapons as a "game-changer" that would have "enormous consequences," but has also said he needs more definitive proof before making a decision about how to respond - and whether to take military action.
There appears to be little push at the moment to intervene directly, and Obama said Friday that he didn't foresee a scenario in which the U.S. would send troops to Syria.
Instead, Defense Secretary Chuck Hagel said Thursday that Washington is rethinking its opposition to arming the opposition. The U.S. so far has balked at sending weapons to the rebels, fearing the arms could end up in the hands of al-Qaida-linked groups or other extremists in the opposition ranks.
It's not the first time that Israel has struck inside Syria since the uprising against Assad began in March 2011.
In January, the Israeli air force is believed to have targeted a shipment of advanced SA-17 anti-aircraft missiles destined for Hezbollah. Israel has not formally admitted to carrying out that airstrike, though officials have strongly hinted they were behind the attack.
The airstrikes follow decades of enmity between Israel and allies Syria and Hezbollah, which consider the Jewish state their mortal enemy. The situation has been further complicated by the civil war raging in Syria.
The war has drained Assad's military and threatens to deprive Hezbollah of a key supporter, in addition to its land corridor to Iran. The two countries provide Hezbollah with the bulk of its funding and arms.
Israel and Hezbollah fought an inconclusive 34-day war in 2006 that left 1,200 Lebanese and 160 Israelis dead.
While the border has been largely quiet since, the struggle has taken other forms. Hezbollah has accused Israel of assassinating a top commander, and Israel blamed Hezbollah and Iran for a July 2012 attack on Israeli tourists in Bulgaria. In October, Hezbollah launched an Iranian-made reconnaissance drone over Israel, using the incident to brag about its expanding capabilities.
Israeli officials believe that Hezbollah's arsenal has markedly improved since 2006, and now boasts tens of thousands of rockets and missiles and the ability to hit trike almost anywhere inside Israel.
Lucas reported from Beirut. Associated Press writers Diaa Hadid in Jerusalem and Bassem Mroue in Beirut contributed to this report.