Zimbabwean police detained 46 people, including a former politician, for attending a lecture and discussion group on mass uprisings in Tunisia and Egypt, an independent lawyers group said.
Police confirmed the arrests at a meeting convened on Saturday by the Zimbabwe branch of the International Socialist Organisation where videos were shown and an agenda item allegedly asked: "What lessons can be learnt by the working class in Zimbabwe and Africa?"
Police spokesman James Sabau told state radio that authorities would clamp down on any alleged plotters of "destabilisation" against the government.
The independent Lawyers for Human Rights said those detained in Harare and expected to appear in court were holding an "academic discussion" on North Africa and deny any wrongdoing.
The group said police were drafting charges against former opposition lawmaker Munyaradi Gwisai, an official of the International Socialist Organisation, and labour and student activists arrested with him.
Police said attendees called for solidarity with Egyptian and Tunisian workers and intended to incite Zimbabweans to hold demonstrations against three decades of authoritarian rule by President Robert Mugabe.