TEHRAN, Iran (AP) -- Iran says three dual nationals and a foreigner held in the country have been indicted on unknown charges.

Iran's semi-official ISNA and Tasnim news agencies on Monday quoted Tehran's prosecutor, Abbas Jafari Dowlatabadi, as announcing charges had been filed specifically against the four and others.

Dowlatabadi named the four charged as:

- Homa Hoodfar , an Iranian-Canadian woman who is a retired university professor;

- Siamak Namazi , an Iranian-American businessman whose father is also held;

- Nazanin Zaghari-Ratcliffe , an Iranian-British woman who works for the Thomson Reuters Foundation, the charitable arm of the news agency; and

- Nizar Zakka, a U.S. permanent resident from Lebanon who has done work for the American government .

By AP