(S (S (S (NP (NP (BASENP (DT An) (NN explosion)) (BASENP (NN yesterday))) (PP (IN in) (BASENP (DT a) (JJ Russian) (NN nightclub)))) (VP (VP (VBD killed) (NP (QP (ADVP (IN at) (JJS least)) (NN 94)) (NNS people))) (CC and) (VP (VBD injured) (BASENP (DT a) (JJ further) (NN 139))))) (COMMA ,) (PP (VBG according) (PP (TO to) (BASENP (NN police) (NNS reports))))) (PERIOD .))