(S (S (PP (VBG According) (PP (TO to) (BASENP (NN police)))) (COMMA ,) (S (NP (BASENP (NN two) (NNS bombs)) (PRN (COMMA ,) (SBAR (WHNP (WDT which)) (S (VP (VBD had) (VP (VBN been) (VP (VBN planted) (PP (IN in) (NP (BASENP (DT the) (NN middle)) (PP (IN of) (BASENP (DT the) (NN pitch)))))))))) (COMMA ,))) (VP (VBD were) (VP (VBN detonated))))) (PERIOD .))