Washington Post reporter Jason Rezaian, who has dual Iranian and U.S. citizenship, was arrested last week, along with his wife, Yeganeh Salehi, a Iranian citizen and writer for the United Arab Emirates newspaper National. The two others arrested, freelance photographers, are U.S. citizens.
State Dept. spokeswoman Jen Psaki said Monday said the United States is "concerned," adding the four should be released immediately.
No charges against the journalists have been reported. An Iranian official said Rezaian was detained for questioning, but offered no other information.
The New York-based advocacy group Human Rights Watch said Tuesday Iran should release the four unless "recognizable charges" are made and a fair trial is guaranteed. Reporters Without borders, an organization based in Paris, noted 65 reporters are currently in jail in Iran, including 10 female reporters. It said in a statement Monday it is "extremely concerned" about Iran's recent arrests of women employed in media.