The defendants -- Mamadou Billo Bah, rapper Alpha Midiaou Bah also known as Djanii Alfa, and Oumar Sylla -- are leaders of an influential political and civil society coalition, whose arrest Tuesday prompted two days of violent protests, were released Friday following a trial in Dixinn, a suburb of the capital, Conakry.
They were seized Tuesday during a press conference and charged with "contempt of court and public injury."
AFP reports that they were beaten and had their clothes torn by police officers.
The prosecutor of the Conakry Court of Appeal, Alphonse Richard Wright, on Tuesday accused Sylla and Bah of "producing and disseminating through a computer system insulting remarks" against the junta-appointed parliament, the National Transitional Council (CNT).
The rapper, Alfa, had recently criticized comments made by the president of the CNT, before being threatened with arrest by the prosecutor, according to his lawyer.
There has been widespread political condemnation of their heavy-handed arrests, which sparked protests in Conakry from Tuesday to Thursday in which 17 police officers were injured, according to the police.
Demonstrators burned tires, set up barricades, knocked over bins and threw projectiles at the police, who tried to disperse them with tear gas.
The protests were among the first against the administration of military ruler Mamady Doumbouya, who took power after a coup in September.
The junta in May banned any public demonstrations that could be construed as threatening public order.
The FNDC had initially called protests for June 23 but indicated they were prepared to give the transitional government a "chance" to set a proposed dialogue in motion.
However, their patience snapped after a meeting with the authorities, which the FNDC slammed as a "parody."
The FNDC coalition had previously been vocal against former president Alpha Conde, who was overthrown in the coup.
Military ruler Doumbouya has pledged to hand over power to elected civilians within three years.
The Economic Community of West African States (ECOWAS) rejected this timeline at a meeting on July 3 but did not announce new sanctions.
Guinea is currently suspended from the bodies of the 15-nation bloc.