MOSCOW (AP) — Thousands of people have gathered in central Moscow to protest against the exclusion of opposition and independent candidates from the city council ballot, the third consecutive weekend of rallies over the issue.

Saturday's demonstration has been sanctioned by city authorities, unlike the two previous protests in which thousands of people were detained, sometimes violently. But some opposition figures have called for an unauthorized march into the capital's center after the permitted rally.

Police on Saturday detained Lyubov Sobol, an unregistered candidate who has become a spearhead of the protest. A video on her Twitter feed showed police breaking into her office as she demanded an explanation from them.

The issue has spread dissatisfaction beyond Moscow; small protests were reported in several Siberian cities on Saturday.