(S (S (PP (IN In) (BASENP (NN four) (JJ separate) (NNS ambushes))) (COMMA ,) (S (BASENP (NNS officers)) (VP (VBD were) (VP (ADVP (RB badly)) (VP (VP (VBN injured) (PP (IN in) (BASENP (DT the) (NNP Paris) (NNS suburbs)))) (PP (IN since) (BASENP (NNP September)))))))) (PERIOD .))