The Committee to Protect Journalists has urged Sudanese authorities "to cease harassing and arresting" journalists and confiscating newspapers covering anti-inflation protests.
Thursday's statement by the New York-based CPJ says seven journalists including one from Reuters and another from AFP were arrested over two days earlier this week and all have been in custody since.
CPJ called for their immediate release saying their families could not determine their whereabouts and whether they are facing any charges.
The Sudanese Journalists Network also reported the arrests.
Sudanese authorities have launched a crackdown on the media after protests broke out in response to lifting of subsidies and devaluing the currency, reforms designed to overhaul the country's battered economy. Earlier in January, authorities confiscated copies of six dailies reporting on the protests.