Three Americans, including the Washington Post’s Iran correspondent, were detained in Tehran on Tuesday, according to “credible reports” the newspaper received.

The Washington Post said Tehran correspondent Jason Rezaian appeared to have been detained in Iran. (Image via Jason Rezaian/Twitter)

The Washington Post said Tehran correspondent Jason Rezaian appeared to have been detained in Iran. (Image via Jason Rezaian/Twitter)

The Post said it was unclear who detained correspondent Jason Rezaian, his wife, Yeganeh Salehi, and two other Americans, identified only as freelance photojournalists. Rezaian holds American and Iranian citizenship; Salehi is an Iranian who has applied for permanent U.S. residency and works for the United Arab Emirates-based newspaper the National.

“We are deeply troubled by this news and are concerned for the welfare of Jason, Yeganeh and two others said to have been detained with them,” Washington Post foreign editor Douglas Jehl said in a statement Thursday. He called Rezaian an “experienced, knowledgeable reporter who deserves protection and whose work merits respect.”

Rezaian has been the Post’s correspondent in Tehran since 2012 and has been based in Iran as a journalist since 2008, the Post said.

State Department spokeswoman Marie Harf told the Post that U.S. officials were aware of the reports that U.S. citizens had been detained.

“Our highest priority is the safety and welfare of U.S. citizens abroad,” Harf said.

Sherif Mansour, the Middle East and North Africa program coordinator for the Committee to Protect Journalists, called on Iran to release the four immediately.

“We call on Iranian authorities to immediately explain why Jason Rezaian, Yeganeh Salehi, and two other journalists have been detained, and we call for their immediate release,” Mansour said in a statement. “Iran has a dismal record with regard to its treatment of imprisoned journalists. We hold the Iranian government responsible for the safety of these four.”