JERUSALEM — Israeli warplanes carried out a strike deep inside Syrian territory on Wednesday, American officials reported, saying they believed the target was a convoy carrying sophisticated antiaircraft weaponry on the outskirts of Damascus that was intended for the Hezbollah Shiite militia in Lebanon.

The American officials, who spoke on the condition of anonymity, said Israel had notified the United States about the attack, which the Syrian government condemned as an act of “arrogance and aggression.” Israel’s move demonstrated its determination to ensure that Hezbollah — its arch foe in the north — is unable to take advantage of the chaos in Syria to bolster its arsenal significantly.

The predawn strike was the first time in more than five years that Israel’s air force had attacked a target in Syria. While there was no expectation that the beleaguered Assad government had an interest in retaliating, the strike raised concerns that the Syrian civil war had continued to spread beyond its border.

In a statement, the Syrian military denied that a convoy had been struck. It said the attack had hit a scientific research facility in the Damascus suburbs that was used to improve Syria’s defenses, and called the attack “a flagrant breach of Syrian sovereignty and airspace.”