(Adds Israeli ministers' meeting, edits)
WASHINGTON, May 3 (Reuters) - Israel has conducted an airstrike in Syria, apparently targeting a building, a U.S. official said on Friday.
The official, speaking on condition of anonymity, declined to elaborate. CNN quoted two unnamed U.S. officials as saying Israel most likely conducted the strike "in the Thursday-Friday time frame" and that Israel's warplanes did not enter Syrian airspace.
CNN said the officials did not believe Israel had targeted a chemical weapons facility. CBS News cited U.S. sources as saying Israel targeted a warehouse.
An Israeli military spokeswoman in Jerusalem declined to comment.
But one source told Reuters that Prime Minister Benjamin Netanyahu had on Thursday night convened his security cabinet in Jerusalem for secret talks - often a sign of imminent action. The source, who would not be identified by name or nationality, did not elaborate on what was discussed at the meeting.
A spokesman for the Israeli Embassy in Washington said: "We cannot comment on these reports, but what we can say is that Israel is determined to prevent the transfer of chemical weapons or other game-changing weaponry by the Syrian regime to terrorists, especially to Hezbollah in Lebanon." Hezbollah fought a 34-day war with Israel in 2006.
There was no other official confirmation of the strike.
Syrian U.N. Ambassador Bashar Ja'afari told Reuters: "I'm not aware of any attack right now."
A White House spokeswoman referred questions on the CNN report to the Israeli government. The Pentagon declined comment.
The CNN report said that during the time frame of the attack, the United States had collected information showing Israeli warplanes flying over Lebanon.
In January this year, Israel bombed a convoy in Syria, apparently hitting weapons destined for Hezbollah, according to diplomats, Syrian rebels and security sources in the region. (Additional reporting by Roberta Rampton, Arshad Mohammed and Phil Stewart in Washington, and Dan Williams in Jerusalem and Lou Charbonneau at the United Nations, Writing by Sandra Maler; Editing by Peter Cooney)