Three US officials told NBC News on condition of anonymity that Israeli F-15 jets attacked the military facilities after Iran had transported its weapons there. According to them, Tehran had been delivering weapons, including surface-to-air missiles, small arms and anti-aircraft missiles for two weeks.
Two officials alleged that the weapons were delivered to Syria for Iranian ground forces for a subsequent attack against Israel.
The Israeli Defense Force has refused to comment on the issue; the Syrian government has also fallen short of commenting on the attacks.
Israel has attacked military facilities in Syria dozens of times, explaining its actions by the need to prevent sophisticated weapons from falling into the hands of groups that Israel deems hostile, including the Lebanese Shiite movement Hezbollah.