The leader of the Ethiopian opposition group, All Amhara People's Organisation, has been allowed to go to the United States for medical treatment.

Professor Asrat Woldeys was serving five years in jail charged with inciting armed struggle among the Amhara people.

He has been in hospital with blood clots in his brain, diabetes and high blood pressure.

He was given permission to go to the US after he wrote a letter of appeal to the prime minister.