Police spokesman James Sabau was quoted in the government-controlled Herald saying the 46 students, trade unionists and political activists seized Saturday were taking part in an illegal meeting where they watched videos "as a way of motivating them to subvert a constitutionally elected government," The New York Times reported.
The agenda, Sabau said, was "Revolt in Egypt and Tunisia: What lessons can be learned by Zimbabwe and Africa?"
The evidence included a video projector, two DVD discs and a laptop.
The prisoners' lawyers said they had not yet been charged but could be accused of "attempting to overthrow the government by unconstitutional means," which carries up to 20 years in prison.
Among the meeting's organizers was Munyaradzi Gwisai, a lecturer at the University of Zimbabwe's law school. Alec Muchadehama, a human rights lawyer who met Gwisai at the Harare Central police station, said detainees told him Gwisai and six others were beaten with truncheons in custody.