The Attorney General, upon the request of the Secretary, shall bring an action to enjoin the violation of, or to compel compliance with, any provision of this chapter or any regulation issued by the Secretary hereunder by any person. Such action shall be brought in the appropriate United States district court for the judicial district in which such person resides or transacts business or in which the violation or omission has occurred or is about to occur. Process in such cases may be served in any judicial district wherein the defendant resides or transacts business or wherever the defendant may be found.