WASHINGTON (Reuters) - The United States on Thursday imposed sanctions on four organizations it said were tied to either Iran's Revolutionary Guard's Quds Force or blacklisted Iranian airline Mahan Air.In a statement posted on its website, the U.S. Treasury Department said it had sanctioned the Fatemiyoun Division, Armenia-based Flight Travel LLC, Iran-based Qeshm Fars Air and the Zaynabiyoun Brigade. It also blacklisted two aircraft.