The intercepted al Qaeda communications that sparked the closure of U.S. embassies in the Middle East and North Africa contained specific words that American intelligence interpreted as a coded message for what they believed signaled a potentially imminent attack , CNN has learned . The coded words directly pointed to the likelihood of a significant al Qaeda attack against an overseas U.S. installation , according to a U.S. source familiar with the latest intelligence . However , the words did not give clues as to a specific location or target , which is what led to closing nearly two dozen embassies and other diplomatic facilities deemed to possibly be at risk . The U.S. intelligence community had been monitoring al Qaeda communications regularly , but was especially concerned about three intercepts . The first was from Nasser al-Wuyhashi , the leader of al Qaeda in the Arabian Peninsula , outlining a possible attack . Another was Ayman al-Zawahiri 's response to that from his position as leader of the global al Qaeda movement . Two weeks earlier , the United States had also monitored a communication from Zawahiri appointing al-Wuyhashi as his deputy . Bergen : What 's behind timing of terror threat . A U.S. official declined to discuss specific code words on the intercepts but told CNN `` there was a sense of imminence , a sense of the overall area at risk and the known actors . There was great concern . '' Members of Congress have indicated that National Security Agency surveillance programs played a role in intercepting and monitoring recent al Qaeda communications . The programs were defended by Secretary of State John Kerry on Tuesday . `` A number of groups in the world have individually targeted not just American interests but free interests in the world , '' Kerry said during press conference in Brasilia , Brazil . `` There have been bombings in many places in the world . Innocent people have lost their lives . And what the United States has been trying to do is prevent these things from happening beforehand by knowing what others might be plotting . '' Separately , a Yemeni official told CNN that a recent drone strike did not injure suspected AQAP bombmaker Ibrahim al-Asiri contrary to an earlier Yemeni news agency report that said he might have been hurt . Three suspects on Yemen 's list of its 25 most-wanted terrorists have been captured and two others killed recently , according to the official . It is not clear if those outcomes were the result of drone strikes or other operations .
Source : Officials believed intercepts indicated potentially imminent attack . Coded words pointed to threat of attack on overseas U.S. installation , officials said . ` ` There was a sense of imminence '' in the intercepted messages , a U.S. official said . Yemeni officials said suspected bomb - maker not involved in drone strike , contrary to reports .