An Egyptian journalist has been charged with joining a terrorist group following the detention of an entire newsroom at the independent fact-checking platform Matsadaash, rights groups say marks an escalation in press restrictions.

Authorities arrested six journalists from Matsadaash, an independent fact-checking and investigative outlet whose name means "don't believe" in Arabic, last week. Officials accused them of operating without a license and publishing false news on behalf of the banned Muslim Brotherhood, according to a statement from authorities.

One of the six has now been charged with joining a terrorist organization. The whereabouts of the other five journalists remain unknown, according to reporting from The Guardian.

Rights organizations have characterized the detentions as part of a broader crackdown on press freedoms in Egypt. The charges against the detained staff connect them to the Muslim Brotherhood, which Egypt's government has designated as a terrorist organization.

Matsadaash operates as an independent fact-checking and investigative news outlet. The platform's detention marks a significant action against a media organization engaged in investigative work.

The case underscores ongoing tensions between Egyptian authorities and independent media outlets. Journalism organizations have called for the release of the detained staff members, though concrete details about legal proceedings or timelines for hearings have not been provided in available reporting.