Al-Qaida vows revenge for Osama bin Laden’s death in first acknowledgment by terror network - The Washington Post
We tend to have this propensity (myself included) to give "one voice" to big entities using that global "they said". In the case of al Qaida especially, that's probably not the best idea.
Regarding this particular statement/news release being discussed. The author (whoever it was) either doesn't have access to a radio or the morning paper, or he is really clumsy with details.