Azerbaijani media say 20 people allegedly affiliated with Iran's Intelligence Ministry were arrested on April 19 as relations between the two countries fray.
According to the official APA news agency, the individuals detained were involved in promoting “the Islamic Republic's propaganda, spreading religious superstitions, attempting to overthrow the secular government of Baku, and engaging in drug trafficking,” all under the guise of religious activities.
The news agency published photographs of the arrested individuals, some of whom were clerics who had studied at the Qom Seminary in Iran, alongside the Islamic republic's religious propaganda flags.
The arrests are the latest in a series of detentions of people who the Azerbaijani government says are working for Iran.
Relations between Tehran and Baku has become increasingly strained in recent months, particularly after an armed attack on Baku's embassy in Tehran.
Baku ordered the evacuation of staff and family members from its embassy in Iran on January 29, two days after a gunman shot dead a security guard and wounded two other people at the facility in an attack Baku said was an "act of terrorism."
Tensions were further heightened following a failed assassination attempt in Baku on an Azerbaijani parliamentarian who has been critical of Iran.
In response to the assassination attempt on Fazil Mustafa, a member of the Azerbaijani parliament, authorities arrested four individuals on charges related to the armed attack and accused the Islamic republic of orchestrating the assassination plot.
Azerbaijan has also accused Iran of backing Armenia in a long-standing conflict over Azerbaijan's breakaway Nagorno-Karabakh region.
Iran has long accused Azerbaijan of fueling separatist sentiments among its sizeable ethnic Azeri minority.