(S (S (BASENP (NNS Observers)) (VP (VBP have) (VP (VBN said) (SBAR (IN that) (S (BASENP (DT the) (NNS attacks)) (VP (VBP bear) (NP (BASENP (DT the) (NNS hallmarks)) (PP (IN of) (NP (BASENP (NNP Lashkar-e-Toiba) (CC or) (NNP Jaish-e-Mohammed)) (COMMA ,) (SBAR (WHNP (BASENP (DT both)) (WHPP (IN of) (WHNP (WDT which)))) (S (VP (VBP are) (VP (VBN believed) (S (VP (TO to) (VP (VP (VB be) (VP (VBN based) (PP (IN in) (BASENP (NNP Pakistan))))) (CC and) (VP (ADVP (RB also)) (ADJP (JJ responsible) (PP (IN for) (NP (BASENP (JJ previous) (NNS attacks)) (PP (IN on) (BASENP (NNP India))))))))))))))))))))))) (PERIOD .))