Police in the Russian capital Moscow have detained some 300 people at an unauthorised protest against the exclusion of many opposition candidates from forthcoming local elections.
Protesters were dragged away from the city hall while others were corralled into nearby streets.
Some of the barred prospective candidates were detained earlier as police carried out searches.
The opposition say their candidates were barred for political reasons.
Officials disqualified about 30 people, saying they had failed to collect enough valid signatures to stand in the 8 September elections.
Moscow's Mayor, Sergei Sobyanin, has called the demonstration a "security threat", and promised to maintain public order.
Anger is widespread among opposition supporters at the way the city is run and the ruling United Russia party.
Opposition leader Alexei Navalny, a fierce critic of President Vladimir Putin, was jailed for 30 days on Wednesday after calling for Saturday's unapproved demonstration.
Police in riot gear pushed back the crowd from barriers surrounding the mayor's office in central Moscow, hauling off detainees to police stations.
A non-governmental monitoring group, OVD-Info, has reported at least 520 arrests while police put the figure at 295.
Local elections usually attract little attention in Russia.
The Moscow authority does not control the city's budget or choose key official appointments, and previous votes have passed without major protests or press interest.
BBC
BDST: 2204 HRS, JUL 27, 2019
SI