(S (S (S (BASENP (PRP They)) (VP (VP (VBD battled) (BASENP (NN security) (NNS forces))) (PP (IN for) (BASENP (NN two) (NNS hours))))) (SBAR (IN before) (S (BASENP (PRP they)) (VP (CC either) (VP (VP (VBD detonated) (BASENP (PRPD their) (NNS explosives))) (CC or) (VP (VBD were) (VP (VBN shot) (ADVP (RB dead))))))))) (PERIOD .))