Burundi took 18 people suspected of involvement in a failed coup against President Pierre Nkurunziza to the high court on Saturday, relatives of some of the accused said.
Earlier, about a hundred demonstrators took to the streets of Bujumbura to protest against Nkurunziza's decision to seek a third term, defying the president's call the previous day for an end to the weeks-long protests.
The east African nation was plunged into deep crisis after Nkurunziza announced he was running for another five-year term, with clashes between police and protesters stirring memories of an ethnically driven civil war that ended a decade ago.
"A lot of us citizens do not want the constitution to be violated as he is not allowed to lead for the third term.... We will demonstrate until he steps down," said Nduwimana Belamie, one of the protesters.
Opponents say Nkurunziza's decision violates the constitution and the Arusha deal to end the war that pitted rebel groups of the majority Hutu population, including one led by Nkurunziza, against the army which was then commanded by minority Tutsis.
The army is now mixed and has absorbed rival factions, but the coup attempt exposed divisions.
The fate of General Godefroid Niyombare, who had announced the president's ouster on Wednesday, was still not clear on Saturday. Loyalist troops calmed the streets of the capital on Friday following clashes between the two factions.
Speaking on condition of anonymity due to fears of reprisals, family members of two of the 18 men taken to court told Reuters the suspects had raw wounds on their bodies and one of them had lost hearing in one of his ears due to a beating in the cells.
One of the men, identified by onlookers as Juvenal Niyungeko, a senior officer, was escorted into the court without shoes and restrained by handcuffs.
It was not immediately clear what charges they were facing.
Christella Harerimana, a lawyer representing three of the suspects, said one of her clients had been walking barefoot since he was arrested, and that he had been held in a house rather than a police cell, contrary to legal requirements.
"They have violated their human rights," Harerimana said, adding it was not clear what would happen next to the men.
The president's spokesman declined to comment on the claims of abuse when contacted by Reuters.
Residents of Bujumbura said they were planning to come out in large numbers on Monday to protest against Nkurunziza's decision to seek a third term.
More than 105,000 people have already fled to neighboring countries, including to Rwanda, with the same ethnic mix as Burundi and which was torn apart by a genocide in 1994 that killed 800,000 mostly Tutsis and moderate Hutus.
