The Washington Post Iranian-American journalist Jason Rezaian, right, and his Iranian wife Yeganeh Salehi, who works for the UAE newspaper National, during a foreign ministry spokeswoman weekly press conference in Tehran, Iran, 10 September 2013. (Stringer/EPA)

Iran confirmed Friday that The Washington Post’s correspondent in Tehran has been arrested on unspecified charges.

Gholam-Hossein Esmaili, director general of the Tehran Province Justice Department, told reporters that the “Washington Post journalist has been detained for some questions and after technical investigations, the judiciary will provide details on the issue,” the official Islamic Republic News Agency (IRNA) reported.

“Iranian security forces are vigilant towards all kind of enemies’ activities, the official added,” IRNA said without elaborating. The brief report did not mention The Post’s correspondent, Jason Rezaian, by name.

Rezaian, 38, a U.S.-Iranian dual national; his Iranian wife, Yeganeh Salehi; and two other U.S. citizens whose identities have not been disclosed appeared to have been detained this week in Tehran, U.S. officials and The Post said Thursday.

Speaking to reporters on the sidelines of annual “Quds Day” rallies, held to express solidarity with Palestinians and oppose Israeli control of Jerusalem, Esmaili shed no light on what prompted the arrests. He went on to denounce”the Zionist regime’s recent crimes in Gaza,” called for the trial of Israeli leaders in international courts and said that “the silence of certain international bodies and states towards Zionist crimes against Palestinians is shameful,” IRNA reported. It was unclear whether those grievances had anything to do with the arrests.

Jason Rezaian, a Washington Post reporter, at the newspaper in Washington. (Zoeann Murphy/AP)

Washington Post foreign editor Douglas Jehl said the newspaper received “credible reports” that Rezaian and Salehi were detained Tuesday evening. It was unclear who detained them.

“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,” Jehl said in a statement.

Jehl said that Rezaian, who has been The Post’s correspondent in Tehran since 2012, “is an experienced, knowledgeable reporter who deserves protection and whose work merits respect.”

Members of Rezaian’s family said they did not want to comment at this time.

Salehi, an Iranian citizen who has applied for U.S. permanent residency, works as a correspondent for the National, a newspaper based in the United Arab Emirates.

The other two American citizens detained with them work as freelance photojournalists.

Esmaili, who serves as chief prosecutor in the capital, was replaced as head of Iran’s prison service and promoted to his current position after protests erupted in April over allegations that political prisoners were beaten by guards at Tehran’s notorious Evin prison.

Marie Harf, a State Department spokeswoman, said that American officials are aware of reports of the detention of three U.S. citizens in Tehran this week.

“Our highest priority is the safety and welfare of U.S. citizens abroad,” she said. Harf said she had no additional information to disclose.

Hamid Babaei, a spokesman for the Iranian mission at the United Nations, said in an e-mail that Iranian diplomats are looking into the reported detentions.

“We will inform you as soon as we receive any news,” Babaei said.

The New York-based Committee to Protect Journalists issued a statement demanding the prompt release of the journalists.

“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,” said Sherif Mansour, the committee’s Middle East and North Africa program coordinator.

Because the United States and Iran do not have formal diplomatic relations, negotiating the release of American citizens detained in Iran is complicated.

Journalists working for Western news organizations have struggled for years to get permission to cover news in Iran. Several have been detained in recent years for a variety of reasons.

Rezaian has been accredited by the government to work for The Post since 2012. He has been based in Iran as a journalist since 2008 and was previously accredited to work for other publications, including the San Francisco Chronicle.