Alexey Mosin was arrested in Yekaterinburg during an event commemorating Boris Nemtsov.

Alexey Mosin was arrested in Yekaterinburg during an event commemorating Boris Nemtsov.

Alexey Mosin was arrested in Yekaterinburg during an event commemorating Boris Nemtsov.

The chairman of Memorial in Yekaterinburg was detained during a flower-laying ceremony in honor of Boris Nemtsov.

According to Vecherniye Vedomosti, Alexey Mosin and former deputy Mikhail Borisov were detained for organizing an unauthorized rally. Mosin was held overnight at the police station, while Borisov was released because he is a member of the electoral commission.

Alexey Mosin, head of the Yekaterinburg-based Memorial, has been fined several times over the past six years for violating regulations governing foreign agent activities. Mosin himself was also charged under the “foreign agent” statute for failing to submit two reports.