Ahwaz, the capital of the Arab-dominated province of Khuzestan, has been the scene of unremitting anti-government protests since the start of the year.
Several hundred people gathered at a Mosque in the district of Shilang-Abad on Friday and rallied to the central district of Lashgar-Abad chanting anti-government slogans.
The paramilitary police quickly moved in to arrest the protestors.
In the ensuing clashes, angry demonstrators threw rocks and sticks at the police.
There were several hit-and-run clashes, after the crowd had dispersed, with several protestors attacking agents of the SSF with swords.
The fate of the detained protestors remains unclear.
Iran has pointed the finger at the United Kingdom as the primary instigator of anti-government violence in Khuzestan.
