WASHINGTON (Reuters) - A U.S. Justice Department probe of the leak of classified information about intercepted messages prior to the Sept. 11 attacks is focusing on Sen. Richard Shelby, former chairman of the Senate intelligence committee, The Washington Post reported on Thursday. The newspaper cited a law enforcement official and congressional sources as saying that the probe has focused on the Alabama Republican who was head of the intelligence panel at the time of the disclosure. The FBI is trying to determine the source of the leaked information that the super secret National Security Agency (NSA) had intercepted two messages...