[1] The organization was accused of committing acts of terror by the Ethiopian government, in hopes of suppressing the Oromo National Movement that was developing at the time.
It was most successful in the south, Arsi in particular, where Oromos had been relegated to the status of tenants on their own land after being conquered by Menelik's forces.
The leadership comprised educated Oromos who had been Amharized but subsequently rediscovered their culture, deciding to fight for a fair share of the spoils of modernization.
Tadesse Birru appeared at organizational rallies in southern towns, delivering speeches critical of the government's policies towards Oromo areas and encouraging the people to demand justice.
[citation needed] By November 1966 the Haile Selassie regime became sufficiently alarmed at growth in the movement's popularity, and decided to arrest its top leadership including Tadesse Birru following a bomb explosion in an Addis Ababa movie house that was attributed to him.