Nairobi/Addis Ababa  - Ethiopia's opposition held a rare demonstration in the capital Addis Ababa Thursday to demand the release of an opposition leader, who is serving a life sentence.

Birtukan Midekssa, the head of the Unity for Democracy Justice (UDJ), was arrested along with dozens of other opposition officials during protests that followed the 2005 elections.

The opposition did well in the polls, but accused the party of Prime Minister Meles Zenawi of stealing the elections.

She was jailed in 2005, but received a pardon. However, she was re-arrested last year and sentenced to life on charges of treason in January.

The BBC reported that passers-by stopped to stare in amazement at the demonstration, the first since the 2005 elections, as several hundred protestors marched on the office of the prime minister to hand in a petition.

Critics say that Birtukan has been jailed because she is viewed as a possible threat to the prime minister's party in the 2010 elections. (dpa)