A opposition coalition on Saturday said it was calling off protests for a week following deadly clashes and a plea for calm by West Africa's regional bloc.
The National Front for the Defence of the Constitution (FNDC), an alliance of political parties, trade unions and civil society organisations, also said gendarmes had arrested its coordinator Oumar Sylla.
Sylla was detained at his home overnight Friday to Saturday and "taken to an unknown destination", Abdoulaye Keita, a lawyer for the FNDC, told AFP.
The FNDC in a statement said it spoke on Friday with the head of the Economic Community of West African States (ECOWAS), Guinea-Bissau's leader Umaro Sissoco Embalo, and agreed to his request to suspend protests for a week.
The truce's only goal is to "give the ECOWAS mediation a chance to find a favourable way out of the crisis in Guinea", the statement added.
The West African state has seen violent clashes between the security forces and demonstrators protesting against the military junta's plans for a three-year transition to civilian rule.
The authorities said one person died in the capital Conakry on Friday, but the FNDC put the total at four.
Another death was reported in Conakry on Thursday.
Fresh protests had been scheduled for 4 August to denounce the "unilateral management of the transition" by the junta, which has banned all political demonstrations until the next election campaign.
A military-dominated government headed by Colonel Mamady Doumbouya has led Guinea since September 2021, when a putsch toppled former president Alpha Condé.
has rejected the junta's proposal to restore civilian rule within three years.