Professor Asrat Woldeyes, who also served as personal physician to former Emperor Haile Selassie, died at the age of 71 in a hospital in Philadelphia on May 14.

He had been allowed to travel there last month after his health deteriorated during five years in jail, where he was sent in 1994 for inciting violence against the state.

Asrat was the first Ethiopian surgeon to be trained in the West, but turned to politics after the current government of Prime Minister Meles Zenawi came to power in 1991.

His All Amhara People's Organisation aimed to protect the rights of the ethnic Amhara people, who felt they were being sidelined by the Tigrayan-dominated government of Meles. He also campaigned for the reunification of Ethiopia after Eritrea seceded peacefully in 1993.

His conviction in 1994 attracted criticism from human rights groups who said the evidence against him was dubious.

Asrat's coffin was escorted from his residence by thousands of young men and women draped in Ethiopia's green, yellow and red national flag.

A leading Ethiopian opposition figure, Professor Asrat Woldeyes, has been buried in Addis Ababa, after a ceremony at the Trinity Cathedral.

Thousands of mourners paid tribute to the leader of the All Amhara People's Organisation, who died in the United States recently.

He was flown there for medical treatment in December after his health worsened while in prison in Ethiopia.

He was imprisoned in 1994 on charges of incitement to insurrection.

The BBC correspondent in Ethiopia says many opposition figures will blame the government for his death.