Iran's intelligence ministry arrested several members of the Baha'i faith on spying charges, state TV reported Monday.
The ministry said in a statement that the suspects were linked to the Baha'i center in Israel and collected and transferred information there.
It is rare for the ministry to report the arrests of members of Baha'i. The report did not say how many had been detained. The detentions raised concerns about potential crackdowns on followers of the religion.
State TV in footage showed one of the suspects saying he was being monitored by agents of the ministry.
Members of the faith in Iran complain about occasional mistreatment and prosecutions in Iran.
Iran already bans the Baha'i, a religion founded in the 1860s by a Persian nobleman considered a prophet by his followers. Muslims consider Muhammad the highest prophet. Since the 19th century many Iranians have converted to the Baha'i sect.
In 2013, Iran's top leader Ayatollah Ali Khamenei, who has final say on all state matters, in a fatwa or religious decree urged Iranians to avoid all dealings with members of the banned Baha'i sect. It supported similar fatwas in the past by other clerics.
Iran allows non-Muslims such as Christians and Jews to worship but has strict laws against seeking converts to other religions.