He said some of the detainees are members of the Bahai ethnic minority group, while others belong to the Tudeh (Communist) party and two have ties to Israel.
The protests erupted after the Tehran-based, government-controlled "Iran" newspaper published a cartoon on May 19 showing a cockroach speaking Azeri.
The unrest started in Tabriz, the main city in the Eastern Azerbaijan province, and rapidly spread to other cities.
Iranian authorities say four demonstrators were killed.
RFE/RL Iran Report
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