say it s getting even stronger. pentagon correspondent barbara star has more. reporter: cnn has learned recent intercepts of messages from senior al qaeda operatives in yemen are renewing concern the group is planning new attacks. the intercepts don t indicate specific targets, but are described by one source as, quote, active plotting. there are multiple indications that al qaeda in the arian peninsula is plotting attacks both within yemen, against u.s. and other western structures as well as overseas. reporter: the group in yemen already well known for the failed underwear bomber attempt to bring down an airplane christmas day 2009. four years later the u.s. intelligence community believes it poses the greatest threat of an attack on the u.s. they re still capable of conducting attacks outside of yemen including plotting attacks