(S (S (BASENP (DT That)) (VP (VBD led) (PP (TO to) (NP (BASENP (DT the) (NNS arrests)) (PP (IN of) (NP (NP (BASENP (NN four) (NNS suspects)) (VP (VBN involved) (PP (IN in) (BASENP (DT the) (NNP Indian) (NNP Mujahideen))))) (COMMA ,) (SBAR (WHNP (WP who)) (S (VP (VBD were) (VP (VBN believed) (S (VP (TO to) (VP (VB have) (VP (VBN been) (VP (VBN involved) (PP (IN in) (BASENP (DT the) (NN 2012) (NNP Pune) (NNS bombings)))))))))))))))))) (PERIOD .))