The ruling junta in the West African state of Guinea warned against joining protests on Tuesday, the second anniversary of its seizure of power.
The ban upholds prohibition of a planned opposition rally calling for a quick return to civilian rule.
Authorities late on Monday released a statement reiterating a decree from May last year that outlawed "movements of support and demonstrations" on public roads.
They warned people against infringing the measure, which they said was taken to "preserve the peace."
The West African state has been run by the military since September 5, 2021, when President Alpha Conde, the country's first freely elected leader, was overthrown.
In the face of international pressure, the junta has promised to restore civilian rule by the end of 2024, purportedly to give it enough time to carry out institutional reforms.
As well as banning all demonstrations, the military regime has arrested a number of opposition leaders and instigated prosecutions against others.
A collective of parties and organisations called Living Forces had called for a "peaceful" march on the takeover anniversary.
In a statement, it accused the junta of having done nothing towards transferring power back into civilian hands.
It highlighted what it said was a lack of progress on a draft constitution, electoral code or body for managing elections, among other things.