Riot police in Zimbabwe's capital, Harare, fired tear gas and beat demonstrators during a crackdown on opposition supporters last Friday.
Despite a ban on protests, scores of people gathered in Africa Unity Square to demonstrate against poverty and state repression.
They were also demanding the release from jail of Chief Ndiweni, a known critic of president Emmerson Mnangagwa. Scores were injured and arrested.
Zimbabwe’s main opposition group, the Movement for Democratic Change, called off the protests at the last minute after failing to overturn a police ban in court.
But protesters had already gathered in the city. Police also banned a march in the city of Bulawayo this week.
About five million Zimbabweans need food aid, according to the United Nations.
Mnangagwa replaced dictator Robert Mugabe in October 2017. But hopes of change have been dashed.
In January, more than a dozen people were killed during a crackdown in Harare against fuel demonstrations.
In the run-up to last week’s planned demonstration, rights groups said six political activists were abducted from their homes at night and beaten by armed men.