Iran's official news agency says more than 15 Iranian and foreign nationals have been arrested for allegedly spying for Israel, attempted assassination and sabotage.
The Tuesday IRNA report says the group planned to assassinate an Iranian expert as well sabotage the country's infrastructure. It added details to a report released earlier this month.
It said the group used Israeli diplomatic missions in Western counties to prepare plans.
The expert's field was not identified. In the past, several Iranian nuclear experts have been killed.
The latest report did not elaborate on nationality of the foreign detainees. It claimed Iranian intelligence also uncovered a spy base of Israeli Mossad in a neighboring country.
Israel's Foreign Ministry refused to comment.