Video released by the Syrians, which purported to show damage from the airstrike, included shots of what appeared to be a burnt-out anti-aircraft battery — experts quoted by the Israeli daily Yedioth Ahronoth Monday said it appeared to a Soviet-made SA-8 system — but also footage of the Syrian Scientific Studies and Research Center complex, the report said.

A senior American military official asserted that it was unlikely that Israel had deliberately targeted the research center, which has been hit by extensive Western sanctions; rather, he said, the Israeli attack included "a small strike package" — a limited number of aircraft, due to Syria's air defense systems — and would thus not "risk doing just a little damage to either" targets by deliberately attacking both.

"They clearly went after the air defense weapons on the transport trucks," he was quoted as saying.

In the wake of the alleged attack northwest of Damascus, not far from the border with Lebanon, US officials indicated that the target was Russian-made SA-17 anti-aircraft missiles, which Syria was in the process of delivering to the Lebanese Shiite militia Hezbollah, in contravention of UN resolutions and explicit agreements between President Bashar Assad and the Kremlin.

Syria, however, maintained that Israel had bombed a "scientific research center," and on Saturday released footage purporting to show the damaged facility.

Reports in various media, including Time magazine, indicated that Israel could have carried out multiple attacks — on the anti-aircraft weapons and on the research center.

On Sunday, Israel appeared to acknowledge for the first time that it had launched an attack, with Defense Minister Ehud Barak indicating that the main target indeed was a shipment of advanced weaponry headed for Hezbollah.

"What happened in Syria several days ago… that's proof that when we say something we mean it," he said at a security conference in Munich. "We say that we don't think [Syria] should be allowed to bring advanced weapons systems into Lebanon."

Assad responded to last week's alleged Israeli strike for the first time on Sunday while speaking with Iranian envoy Saeed Jalili in Damascus. He alleged that the attack "exposes the true role conducted by Israel" in aiding the "external forces hostile [to Syria]" that he claims are behind the move to oust him from power. His country has been engaged in a bloody civil war for the past nearly two years in which 60,000 Syrians have been killed.