"In total, 3,904 people have been released by the police until today," the police said in a statement on radio and national television.

According to the federal police, 509 people remained detained at the Zewai camp, and 190 were still being held at the Sendafa camp, 40 kilometers north of Addis Ababa.

The legislative elections held on May 15 -- which the opposition claimed was marked by fraud -- had been the most contested of the country's history, with at least 36 deaths in the violence that followed.