(S (S (BASENP (DT The) (NNP United) (NNPS States)) (VP (VBZ has) (VP (VBN said) (SBAR (IN that) (S (QT (DQL ``) (BASENP (JJ regional) (NNS extremists)) (DQR '')) (VP (MD may) (VP (VB be) (VP (VBG targeting) (NP (BASENP (NNP Air) (NNP Uganda) (NN airplane) (NNS flights)) (PP (IN between) (NP (BASENP (NNP Southern) (NNP Sudan)) (CC and) (BASENP (NNP Uganda))))))))))))) (PERIOD .))