The minister did not specify how many people have been detained.
He also did not identify those detained or clarify whether they were dual nationals.
He described those detained as "local agents" and "part of a network used by" Haleh Esfandiari and Kian Tajbakhsh.
Esfandiari is an academic at the U.S.-based Woodrow Wilson International Center for Scholars. Tajbakhsh is a consultant with the Soros Institute.
They were detained separately while visiting their relatives in Iran in May.
Iranian officials have said that the detained Iranian-American scholars are part of a U.S.-backed plot aimed at destabilizing Iran’s Islamic establishment.
Two other Iranian-Americans have been also barred from leaving Iran. One of them, Ali Shakeri, a peace activist, is reportedly in jail. Parnaz Azima, a broadcaster with Radio Farda, is free on bail.
The detention of the Iranian-Americans has exacerbated already-tense U.S.-Iranian relations.
Nevertheless, Iranian Foreign Minister Manuchehr Mottaki today said Tehran is ready to consider high-level talks with the United States.
(Reuters, AP, AFP)