Shares of U.S.-listed Chinese companies fell on Thursday after a top securities regulator said U.S. criminal authorities are investigating accounting irregularities at Chinese companies listed on U.S. stock exchanges.

Among companies that fell, Inc dropped 7.8 percent to $48.99, Baidu Inc lost 6 percent to $114, China Sky One Medical Inc declined 7.6 percent to $2.19, while Sina Corp fell 8 percent to $74.60.

There are parts of the Justice Department that are actively engaged in this area, Robert Khuzami, director of enforcement at the U.S. Securities and Exchange Commission, told Reuters in an interview conducted this week and published on Thursday.

(Editing by Padraic Cassidy)