Iran sanctions expanded, firms and persons blacklisted

WASHINGTON, DC - The United States ratcheted up its sanctions against Iran on Thursday, blacklisting a number of firms and individuals for contributing to what it says is an effort to acquire nuclear weapons.

The U.S. Treasury said it was also identifying a number of "front companies and banks" linked to nuclear proliferation, an attempt to make it harder to evade existing sanctions.

(Reporting by Pedro da Costa; Editing by Jackie Frank)