This party, the Coalition of National Unity and Democracy (CUD) has had around 1,000 of its members, including its entire leadership, arrested in a vast nation-wide operation, according to one member who spoke to AFP on condition of anonymity.
A diplomat based in Addis Ababa and witnesses told AFP Wednesday's violence erupted when police moved in to certain districts to arrest opposition leaders, prompting angry residents to throw stones or erect barricades.
The latest fatalities bring to at least 35 the number of people killed and to nearly 200 those injured in two days of unrest in Addis Ababa, where the opposition has defied government warnings not to stage protests against May elections it insists were rigged.
Wednesday's deaths were reported by medical sources in three of the city's five main hospitals.