(S (S (S (BASENP (DT The) (NN eight) (JJ Russian) (NNS jets)) (VP (VBD were) (VP (VBG flying) (PP (IN in) (NP (BASENP (NN airspace)) (VP (VBN patrolled) (PP (IN by) (BASENP (NNP Nato))))))))) (COMMA ,) (S (NP (BASENP (NNS officials)) (PP (IN from) (BASENP (DT the) (NNP UK)))) (VP (VBD claimed)))) (PERIOD .))