(S (S (PP (IN After) (NP (BASENP (JJ several) (NNS hours)) (PP (IN of) (BASENP (JJ unsuccessful) (NNS negotiations))))) (S (BASENP (JJ unarmed) (NN security) (NNS forces)) (VP (VP (VBD entered) (BASENP (DT the) (NN complex))) (S (VP (TO to) (VP (VB begin) (S (VP (VP (VBG removing) (BASENP (NNS people))) (PP (TO to) (NP (BASENP (NNS buses)) (VP (VBG waiting) (ADVP (RB outside))))))))))))) (PERIOD .))