The National Constitutional Assembly called the protest march to urge that a caretaker government be established pending the resolution of the current impasse in power-sharing talks between President Robert Mugabe's ZANU-PF and the Movement for Democratic Change of prime minister-designate Morgan Tsvangirai.
NCA Chairman Lovemore Madhuku, a prominent critic of President Mugabe, was summoned to a police station before the demonstration but was not detained, the group said.
From Harare, correspondent Irwin Chifera of VOA's Studio 7 for Zimbabwe reported on the demonstration, which brought a harsh police response.
NCA National Director Earnest Mudzengi gave reporter Patience Rusere details on Madhuku's brief detention, and promised more protests in the days ahead.
The demonstration followed a summit in Johannesburg on the weekend of
heads of state and government of the Southern African Development
Community, who urged Mr. Mugabe and Tsvangirai to put in place the
national unity government envisioned under a Sept. 15 power-sharing
agreement. But the SADC summit displeased the MDC in recommending that
control of the Home Affairs Ministry be shared by ZANU-PF and the MDC.
In Washington, a spokesman for the U.S. State Department said the American government was disappointed at SADC's failure to bring the power-sharing parties together.
VOA Correspondent David Gollust reported from the Department of State.
VOA reporter Peter Clottey sought perspective on the summit fallout from political analyst Glen Mpani in Cape Town, South Africa, who said SADC's resolution splitting the difference between the two sides dealt a major setback to the quest for a crisis solution.
Tsvangirai's MDC grouping denied reports he had sought a meeting with Mr. Mugabe.
Spokesman Nelson Chamisa of the Tsvangirai MDC formation dismissed allegations by the state-controlled Herald newspaper that the opposition party was "facilitating training of militia in a neighboring country with the aim of destabilizing" Zimbabwe.
Chamisa told reporter Carole Gombakomba of VOA's Studio 7 for Zimbabwe that the party's leadership will meet Friday to consider next moves following the SADC summit.More reports from VOA's Studio 7 for Zimbabwe...