Zimbabwe's opposition leader Morgan Tsvangirai has been taken to hospital after appearing in court with injuries following two days in police detention.
Tsvangirai was led into court, his face was cut and swollen
He was taken from Harare magistrates court with several other activists, many of them bandaged, for treatment.
They were badly beaten in custody after being detained at a banned opposition rally on Sunday, supporters said.
One person was shot dead as riot police broke up the meeting, called to discuss the political and economic crisis.
The BBC's Southern Africa correspondent, Peter Biles, says the court was surrounded by riot police as Mr Tsvangirai and around 100 other detainees were brought in.
He stood next to Arthur Mutambara, the leader of a rival MDC faction, while many of the activists sang and chanted, AFP news agency reported.
Mr Tsvangirai's lawyer, Innocent Chagonda, said the Movement for Democratic Change (MDC) leader had sustained head injuries, bruising to his body, and was limping.
Prosecutor Florence Ziyambi said detainees would be allowed to receive medical attention, before they were taken away in ambulances.
Our correspondent says it is not yet clear what charges may be brought against Mr Tsvangirai and the other activists.
The police action against Sunday's meeting in Harare has been strongly condemned by United Nations Secretary General Ban Ki-moon, and by the United States and European Union.
TSVANGIRAI'S LEGAL TROUBLES
2003: Charged with treason - later dropped
2002: Lost election to Mugabe, charged with treason - later dropped
2000: Charged with treason - later dropped
2000: MDC won 57 parliamentary seats
1999: Helped form MDC
Mr Ban's spokeswoman said the arrests "violate the basic democratic right of citizens to engage in peaceful assembly".
The US called the crackdown "brutal and unwarranted" and called for the activists to be released.
"We hold President Robert Mugabe and the government of Zimbabwe accountable for the safety and well-being of those in custody," White House spokesman Sean McCormack said.
However, few of Zimbabwe's neighbours have condemned its policies.
A South African foreign ministry spokesman said: "We have constantly maintained that the solutions to the problems of Zimbabwe will be resolved by the people of Zimbabwe."
MDC politician Roy Bennett, who is now living in exile in South Africa, regretted that stance.
"It is very sad that our neighbours continue to keep quiet about the brutal situation," he said.
Zimbabwe's Information Minister Sikhanyiso Ndlovu said the police's action was justified as they were attacked by opposition activists.
"The opposition has been involved in violence, caught by police with weapons of destruction and destroying cars and stores and beating up people," he told the BBC's Network Africa programme.
"They've been beating up police you know. That is what government cannot tolerate."
The government said the rally breached a ban on political gatherings imposed after violence at a demonstration last month.
Civil discontent in Zimbabwe is rising over the country's economic crisis, with chronic unemployment and inflation running at more than 1,700% - the highest in the world.