(Reuters) - The U.S. embassy in Addis Ababa advised all U.S. citizens to leave Ethiopia as soon as possible, a statement on their website said on Friday, after an alliance of anti-government forces threatened to march on the capital city.

       "The security environment in Ethiopia is very fluid. We advise U.S. citizens who are in Ethiopia to leave the country as soon as possible," the statement said.

       (Reporting by Addis Ababa newsroom; Editing by Toby Chopra)