Israeli officials confirmed Saturday that an airstrike against Syria was aimed at missiles allegedly being transferred to anti-Israeli Islamist militants and not the Assad regime’s chemical weapons stockpiles.

{mosads}About 16 Israeli warplanes breached Lebanese airspace Thursday overnight and attacked targets inside Syria, CNN first reported late Friday. An Israeli official told the Associated Press on Saturday that the strike aimed to destroy “advanced, long-range ground-to-ground missiles” being transferred to the Iran-backed Lebanese group Hezbollah, which the United States considers a terrorist group.

“Chemicals maybe get a lot of press and attention,” an Israeli official told The New York Times, “but one of the clear things worrying us is advanced conventional weapons.”

The Israeli embassy in Washington declined to comment about the strike, but said in a statement that “Israel is determined to prevent the transfer of chemical weapons or other game-changing weaponry by the Syrian regime to terrorists, specially to Hezbollah in Lebanon.”

The strike comes as President Obama has warned that reports that Syria has used chemical weapons, if confirmed, would be a “game-changer” that would spark greater U.S. involvement in the two-year-old civil war. He said Friday that he did not envision having to deploy troops on the ground but could not definitively rule out such a scenario.

Bashar Assad’s regime did not confirm the strike, possibly because it does not want to set in motion a retaliatory attack against Israel that would likely decimate its air force. This is the second Israeli strike against arms transfers to Hezbollah since the Syrian civil war began; in January, the Israeli air force is believed to have destroyed a shipment of SA-17 anti-aircraft missiles destined for Hezbollah, although Israel did not publicly confirm its role.

Iran is one of the few countries that backs Assad and is believed to have sent military advisers to help train and support the regime’s armed forces. Ali Akbar Velayati, an aide to Iran supreme leader Ayatollah Ali Khamenei, warned earlier this year that any “attack on Syria is considered (an) attack on Iran and Iran’s allies.”