Amnesty International has declared Russian opposition activist Sergei Udaltsov a prisoner of conscience and called for his immediate release from prison.
Udaltsov, who heads the Left Front opposition movement, was sentenced to 15 days in jail on August 1 for participating in an unsanctioned rally promoting freedom of assembly the day before.
Amnesty International said it had "serious" grounds to believe the jail sentence was politically motivated.
The rights group added that Udaltsov's repeated arrests in past years suggested the activist was being persecuted exclusively for his peaceful exercise of his right to free speech and free assembly.
Udaltsov, who heads the Left Front opposition movement, was sentenced to 15 days in jail on August 1 for participating in an unsanctioned rally promoting freedom of assembly the day before.
Amnesty International said it had "serious" grounds to believe the jail sentence was politically motivated.
The rights group added that Udaltsov's repeated arrests in past years suggested the activist was being persecuted exclusively for his peaceful exercise of his right to free speech and free assembly.