Police in Harare on Monday released the last of more than 200 activists of the Movement for Democratic Change who were arrested on Saturday in a raid on the headquarters of the MDC faction headed by Morgan Tsvangirai.
Some of the activists said police beat and tortured them while in custody.
Correspondent Thomas Chiripasi of VOA's Studio 7 for Zimbabwe reported that the activists were released with no charges brought against them.
Officials of the opposition faction called the arrests arbitrary and said they endangered the mediation efforts currently being pursued by South African President Thabo Mbeki on behalf of heads of state of the Southern African Development Community.
Calls to a police spokesman and Information Minister Sikhanyiso Ndlovu seeking comment on the alleged police beatings and torture were not answered.
Tsvangirai faction spokesman Nelson Chamisa said the weekend raid on a meeting of youth activists was part of an ongoing campaign by the government and the ruling ZANU-PF party to silence dissent and paralyze the political opposition.
Chamisa told reporter Jonga Kandemiiri of VOA's Studio 7 for Zimbabwe that the opposition would continue nonviolent action despite official provocation.