(S (S (BASENP (DT The) (NN explosion)) (VP (VBD occurred) (PP (IN in) (NP (BASENP (NNP Nazran)) (COMMA ,) (NP (BASENP (DT the) (JJ main) (NN city)) (PP (IN in) (NP (BASENP (DT the) (NN region)) (PP (IN of) (BASENP (NNP Ingushetia)))))))))) (PERIOD .))