Zimbabwean police arrested 36 members of the activist group Women of Zimbabwe Arise and a men's counterpart organization as they marched through Bulawayo and tried to present government officials what they called a "people's charter."
Activists said 24 demonstrators sustained injuries including broken limbs. Among those arrested were WOZA National Coordinator Jenni Williams and another leader, Magodonga Mahlangu, as well as six women carrying their babies.
Sources say police descended and broke up the march as participants tried to present the document to officials at government offices in Zimbabwe's second-largest city.
WOZA organizers said 24 people were seeking medical attention for injuries.
Elsewhere on Wednesday, national protests called by the Save Zimbabwe Campaign, an ad hoc coalition, failed to take off in Harare, Bulawayo and other cities. Sources in the protest movement said internal differences over strategy had cropped up.
Civil society sources said the campaign, in which Zimbabweans have been urged to voice their discontentment by making noise at lunch time on Wednesdays, is backed by the Zimbabwe Congress of Trade Unions, the Zimbabwe National Students Union, the Crisis in Zimbabwe Coalition and all of the main opposition parties.
But other members of the coalition - including the influential National Constitutional Assembly, said some sources - question the effectiveness of such protests. And the separate WOZA protest signaled a clear divergence of strategy in Bulawayo.
An informal survey of sources in Harare and Bulawayo late Wednesday suggested the noise protest - the second in a series - had failed to significantly materialize, although some civic activists heading home from a meeting blew horns in the capital. Campaign insiders said some people were fearful while organization had been poor.
A spokesman for the Christian Alliance, which chairs the Save Zimbabwe Campaign, played down the apparent failure of Wednesday's "sound of freedom" protest.