"Thirty individuals who cause tense situation in the country for the last days have been arrested," Iran's National Security Minister Gholam-Hussein Mohseni-Ejei said.
He said the ministry will provide detailed information about the arrested in coming days.
The National Security Ministry and law enforcement agencies reinforced work to find and arrest those who cause tension in the country by joining demonstrators, Ejei said.
Mass demonstrations are underway in Iran against results of presidential vote. Supporters of the former presidential candidate Mir Hossein Mousavi claim that election results have been falsified. Mousavi did not accept his defeat and accused his rival Mahmoud Ahmadinejad of rigging election results. Latest developments claimed 25 lives. Hundreds of political activists have been arrested.