U.S. prosecutors have brought charges against Zafer Caglayan, Turkey's former economy minister, and Suleyman Aslan, the former General Manager of Turkish state-owned bank Halkbank, for "conspiring to use the U.S. financial system to conduct hundreds of millions of dollars' worth of transactions" on behalf of the Iranian government and other Iranian entities.  Two others were charged alongside Caglayan and Aslan.  The four individuals also are accused of laundering funds, lying to U.S. officials about the transactions, and defrauding financial institutions.  The charges stem from a sanctions evasion case against Reza Zarrab, a Turkish-Iranian gold trader who was arrested in the United States last year.