Iran's Fars and IRNA news agencies quoted the head of the intelligence service in the western province of Kermanshah as saying a total of 20 people have been arrested, including Iranians and foreigners.
The official, identified only as Karimi, said the alleged spies were trained for economic, military, political, cultural, and social espionage.
Tehran has previously accused the United States, Israel, and Britain of operating in Iran to destabilize the Islamic republic.
In May, Iran claimed spy networks with alleged links to U.S. agents in Iraq had been smashed in western, southwestern, and central Iran.
Tehran said the spy networks were supported by groups in Iraq with the aim of expanding their activities to five provinces in western and southwestern Iran and to the capital.
Also in May, Iran confirmed that charges had been filed alleging that three U.S.-Iranian citizens, including Parnaz Azima, a journalist who works for the U.S. government-funded Radio Farda, acted against Iran's national security.
The two others are scholars Kian Tajbakhsh and Haleh Esfandiari.
In February, Iranian media quoted Intelligence Minister Gholamhussein Mohseni-Ejei as saying Iran has identified 100 spies working for the United States and Israel in border areas of Iran. The alleged spies intended to gain access to military and political information.
The minister added that a number of Iranians who sought to take part in espionage training abroad have also been arrested.
(dpa, AFP, AP, Reuters)