[Kyra Phillips, Cnn Anchor:] On this second anniversary of the 911 attacks, the government is issuing a worldwide caution to Americans and is warning of the threat of another more devastating al Qaeda attack. The State Department warning comes on the heels of that videotape, showing Osama bin Laden and his top deputy, Ayman al- Zawahiri. Our David Ensor joins us now with more details. David, what do you know?
[David Ensor, Cnn National Security Correspondent:] Well, Kyra, CIA officials are saying that the tape is that they have high confidence the voice of al Qaeda's No. 2 man, Ayman al-Zawahiri, is on the tape broadcast Wednesday, but that technical analysis of the voice that is said to be Osama bin Laden is inconclusive. Technical analysis of the tape is continuing but they're saying it is possible they may not be able to say whether or not it's bin Laden's voice, since the quality of that part of the recording is not good. The Zawahiri stuff is on microphone. If it's bin Laden, he's not on the mike. The official noted that al-Zawahiri makes specific references to events that are not so far in the past, proving that his portion must have been recorded in recent months, but the voice alleged to be bin Laden makes no such references. So it could be old, or it could be new Kyra.
[Phillips:] Let's talk about how you would know, if indeed, it was an old tape or not. You and I were talking earlier about time references.
[Ensor:] Well, as I said, Zawahiri makes some reference to events not too far in the past, bin Laden does no such thing. And in fact, CIA officials say it hasn't been since this other tape, November 2002, that bin Laden last referred to an event that proved the tape had been recorded recently. He referred to the killing just before that of an American diplomat in Amman. On this tape, he makes very general statements against the infidel and so on, and calling his followers to attack Americans. But he says nothing specific that allow us to know when the tape was recorded. As far as the video's concerned, some officials believe it may be old videotape. Could even be a year or two, or three, old. They're not convinced it was recorded in spring, this year. Although if you look at the vegetation in the tape, you can see it must have been filmed in spring of some year, or another Kyra.
[Phillips:] David, also, we were talking about the increased chatter. What are you hearing from your sources?
[Ensor:] I'm afraid I'm hearing that U.S. intelligence is picking up increased chatter, as you put it. The kind of people that they monitor, would-be terrorists, other suspects, are talking amongst each other about a possible attack coming against U.S. or Western targets today, tomorrow, the next day, in the near future. But there's nothing specific or credible as to where the target might be or when the specific attack might occur. Baghdad is one of the locations that they do confirm is of concern. But they say there's intelligence suggesting other locations, too. But nothing specific and credible Kyra.
[Phillips:] National Security Correspondent David Ensor. Thanks, David. TO ORDER A VIDEO OF THIS TRANSCRIPT, PLEASE CALL 800-CNN-NEWS OR USE OUR SECURE ONLINE ORDER FORM LOCATED AT www.fdch.com