Iranian police say they have arrested several armed rioters during overnight clashes between pro-Moussavi demonstrators and anti-riot police, Press TV reported.
"Members of an anti-revolutionary group known as 'Iranian Empire Society' carrying a significant amount of explosives and weapons have been arrested in Tehran, Deputy Police chief Ahmad Reza Radan told reporters on Tuesday.
Yesterday's mostly peaceful mass rally in support of Iran's June 14 candidate Mir-Hossein Moussavi turned into an ugly scene when unidentified gunmen fired shots into the crowd.
The shooting left more than seven people dead, while injuring several more in the capital Tehran.
"Those arrested have confessed to having plans for creating chaos and unrest," Radan said adding that details of their reported plans will be publicized soon.