Local Iranian media reports say the authorities have arrested three lawyers as they returned from trips abroad.
The three lawyers -- Maryam Kianersi, Maryam Karbasi, and Sara Sabaghian, all women -- were arrested on security charges upon arrival at the country's Imam Khomeini Airport.
The three had signed an open letter in September calling for the release of leading human rights lawyer Nasrin Sotoudeh.
Sotoudeh represented many of the opposition activists and politicians arrested in the government crackdown on dissent following the country's disputed 2009 presidential election.
Kianersi, Karbasi, and Sabaghian also signed a petition in April that opposed a proposed law easing restrictions on polygamy.
compiled from agency reports