(Adds demonstration at prosecutor's office, background)
TEHRAN, June 18 Two children of former president Akbar Hashemi Rafsanjani, a political opponent of President Mahmoud Ahmadinejad, have been barred from leaving Iran, the semi-official Fars News Agency said on Thursday.
Rafsanjani's daughter Faezeh addressed supporters of defeated presidential candidate Mirhossein Mousavi on Tuesday when they gathered near the state television building in Tehran in defiance of a ban on opposition protests.
Fars did not give a source for its report. It said around 300 people demonstrated outside the Tehran prosecutor's office on Thursday calling for Faezeh and her brother Mehdi to be arrested.
Rafsanjani, who remains a powerful figure in Iran, supported Mousavi in the June 12 election. Official results showed Ahmadinejad won by a landslide but Mousavi says the vote was rigged, a charge the authorities reject.
Rafsanjani reacted furiously when Ahmadinejad accused him on television of corruption, publicly urging Iran's Supreme Leader Ayatollah Ali Khamenei to rein in the president. (Reporting by Hashem Kalantari; Editing by Alison Williams)