Two relatives of former U.N. Secretary-General Ban Ki-moon were charged in an indictment unsealed Tuesday with plotting to bribe a Middle East official to influence the $800 million sale of a building complex in Vietnam. Ban’s nephew, Joo Hyun Bahn, was released on $250,000 bail over the objections of prosecutors, who sought to deny bail on the grounds that he is a flight risk and a financial threat to his community.