Guinean security forces on Monday arrested at least 12 journalists who were demonstrating against censorship, using tear gas to disperse the protest, according to organisers and local media.
The Private Press Union of Guinea (SPPG) had called a march in the capital Conakry to demand authorities lift restrictions placed on the popular Guinee Matin news site.
Since August, the site has only been accessible within Guinea with the use of a VPN.
Reporters Without Borders has created a mirror site to allow people inside the West African country to read its content.
Guinea's ruling junta, which seized power in September 2021, has not provided any explanation for the blockage.
"We intended to gather at the roundabout by the port," Abdouramane Diallo, an SPPG official, told AFP.
"The mixed police and gendarmerie forces gassed us," he said, adding that one journalist was slightly injured.
The secretary-general of the SPPG is reportedly among the dozen journalists arrested.
They were brought to a court for criminal participation in an illegal assembly.
The junta has banned protests since 2022.
Four press associations said in a joint statement that they "condemn this gratuitous violence committed against journalists" and "demand their immediate and unconditional release".
"The press associations call on the national and international community to witness the serious decline in freedom of expression and democracy," they added.