NEW : Witnesses recount gunmen shooting patrons , hurling grenades . The Associated Press reports that the attack began at a popular nightclub in central Rio de Janeiro, where hundreds of people were celebrating New Year's Eve. The casino fire left 52 dead and shocked Mexico . Video from a gas station and the casino provided evidence that the suspects used gasoline as an accelerant at the casino , the officials said . Mexican officials showed off five suspects to reporters Tuesday .
NEW : Witnesses recount gunmen shooting patrons , hurling grenades . The Associated Press reports that the attack began at a popular nightclub in central Rio de Janeiro, where hundreds of people were celebrating New Year's Eve. The casino fire left 52 dead and shocked Mexico . Mexican officials showed off five suspects to reporters Tuesday .