While the attack targeted Russian-made SA-17 missiles and their launchers, video shown on Syrian television backs up assertions that the research center also suffered moderate damage, The New York Times quoted US officials as saying.
The complex, the Syrian Scientific Studies and Research Center, located north of Damascus has been the target of American and Western sanctions for more than a decade because of intelligence suggesting that it was the training site for engineers who worked on chemical and biological weaponry.
The paper quoted a senior US military official as saying that any damage (to the complex) was likely "due to the bombs which targeted the vehicles" carrying the anti-aircraft weapons and from "the secondary explosions from the missiles."
The official said that "the Israelis had a small strike package", meaning that a relatively few fighter aircraft slipped past Syria's Russian-made air defences to hit the target. "They clearly went after the air defense weapons on the transport trucks," the official told the paper.
There is still much that is not known about the attack, and there have been contradictory descriptions of it. Initial reports suggested that the anti-aircraft missiles - which the Israelis feared were about to be moved to Hezbollah forces in Lebanon - were hit near the Lebanese border.
Subsequent reports suggest there were multiple attacks conducted at roughly the same time, the NYT said.
Israel, which had been silent on the issue, yesterday gave the first indirect confirmation of the attack.
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Speaking at a security conference in Munich, outgoing Israeli defense minister Ehud Barak referred to the attack as "another proof that when we say something we mean it."
Israel had warned that if it saw Syrian chemical weapons on the move, it would act to stop them.
Syrian President Bashar al-Assad has threatened to retaliate, saying the raid "unmasked the true role Israel is playing, in collaboration with foreign enemy forces and their agents on Syrian soil."
The event fuelled fears of a regional spillover of the Syria's 22-month conflict which has left 60,000 people dead.