A decree declaring dissolution of the National Front for the Defense of the Constitution [FNDC], signed by Territorial Administration Minister Mory Conde, was authenticated by AFP on Tuesday.
"The de-facto group called the National Front for the Defence of the Constitution, is dissolved... with effect from the date of signature," the ruling said.
The decree said the FNDC's "operational mode is based on violent attacks (perpetrated) during banned demonstrations, attacks against individuals who do not share their ideology, and targeted attacks against the security forces."
The organization has "the behavior of combat groups and private militias... threatening national unity, public peace and cohabitation", it said.
Demonstrations broke out in Guinea on July 28 and 29 over perceptions that the junta was dragging its feet on its restoring civilian rule, leaving five dead.
An alliance of political parties, trade unions and civil groups, the FNDC spearheaded protests against former president Alpha Conde before his ouster in a coup last year.
Friction has been growing for months between the FNDC and the junta, culminating in an announcement by the coalition on Monday that it would stage demonstrations on August 17.
In 2010, Alpha Conde, today aged 84, became the country's first democratically elected president.
But his popularity dived in his second term as critics accused him of authoritarianism, and opposition protests were violently repressed.
Dozens died, the overwhelming majority of them civilians, in protests launched by the FNDC.
Last September, as anger mounted over Conde's successful bid for a third term -- a move he defended on the grounds of a change to the constitution -- mutinous troops rebelled.
Junta strongman Mamady Doumbouya has pledged to return power to elected civilians within three years.
The timeline has put the junta into conflict with the region's bloc, the Economic Community of West African States (ECOWAS).
ECOWAS' chair, Guinea-Bissau President Umaro Sissoco Embalo, said late last month that he had convinced the junta to shorten the transition to two years. The figure has not been confirmed by Guinea.
