An Egyptian journalist has been charged with joining a terrorist group following the detention of six staff members from the independent news platform Matsadaash, according to the Guardian.

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

One of the six has now been formally charged with joining a terrorist group. The whereabouts of the other five detainees remain unknown, the Guardian reports.

Human rights groups have characterized the arrests as part of a crackdown on press freedoms in Egypt. Calls have been made for the release of all Matsadaash staff members.

The charges and detentions reflect ongoing tensions between Egyptian authorities and independent media outlets. Matsadaash operates as a fact-checking and investigative platform, a category of journalism that has faced increasing scrutiny in the country. The government's framing of the journalists' work as unlicensed publishing and association with a banned political movement represents the basis for the terrorism designation, though specifics of the evidence against individual detainees have not been detailed in available reporting.