New York City police stepped up security around Deutsche Bank locations in the city on Thursday after the German bank\'s Frankfurt headquarters Bank received a mail bomb Wednesday.New York Police Department spokesman Paul Browne told local media that it advised Shield, a security program for private institutions in New York, to be \"extra careful\" of similar suspicious packages received by mail.In addition, all New York banks were \"being advised to take precautions\" after the mail bomb threat, according to NYPD.Deutsche Bank confirmed on Wednesday it had received a mail explosive device and handed it over to the police for investigation.An Italian anarchist group on Thursday claimed responsibility for the mail bomb sent to the CEO of Deutsche Bank and indicated there may be two more explosive packages still out there, according to German authorities.