Iran's semi-official Tasnim news agency says authorities have accused a detained American-Iranian dual citizen of "acting against national security."

The Wednesday report did not name the suspect, but said he was arrested in the northern city of Gorgan in July, and so appeared to be referring to Robin Shahini. Authorities did not announce any allegations when Shahini was apprehended on July 24.

The Tasnim report says the suspect was arrested by the Revolutionary Guard on charges of "acting against national security, having relations with anti-revolutionary elements and collaborating with enemy states."

Several dual citizens have been arrested on security-related allegations since Iran reached a landmark nuclear agreement with world powers last year. Iran's security forces and judiciary are largely dominated by hard-liners opposed to the agreement.