MOSCOW (AP) — Authorities in Moscow are warning that a planned attempt to hold an unauthorized protest on Saturday will bring a strong police response.

Police violently detained more than 1,000 demonstrators on July 27 at an unsanctioned protest against the exclusion of some independent candidates from the ballot for the Moscow city council election; an arrest-monitoring organization put the number detained at 1,373. Police beat some demonstrators with batons.

Despite the violence, activists have called for a march through central Moscow on Saturday.

The city prosecutor's office on Friday issued a statement warning that the attempt would be "a direct violation of the law. Law enforcement agencies will be forced to take all necessary measures to curb provocations."