An Iranian opposition website says security forces have arrested two daughters of opposition figure Mir Hossein Mousavi, who along with his wife, has been under house arrest for nearly two years.
The report published Monday by Kaleme.com says the daughters, Zahra and Narges, were detained after security forces searched their home.
It did not say where they were taken. Iranian officials have not confirmed the arrests.
The report comes as Iran gears up for June's presidential election to pick a successor to President Mahmoud Ahmadinejad.
Mousavi was a leading presidential candidate in the 2009 elections, which gave Mr. Ahmadinejad a second four-year term.
Mousavi and another opposition figure, Mehdi Karroubi, have been under house arrest since February 2011.