Updated at 3:15 p.m. Aug. 3
Russian police detained 685 people Saturday at a protest in Moscow against what they saw as unfair elections, a monitoring group said.
The nongovernmental group OVD-Info, which monitors arrests, said the arrests were made along thoroughfares in the city center, where Russian officials said unauthorized opposition protests were being held.
Prominent activist Lyubov Sobol was among those who were detained, as were six journalists, according to the French news agency AFP. Police took Sobol into custody from a taxi minutes before the protest began.
Activists called for the demonstration after a number of opposition candidates were prohibited from participating in Moscow's city council election being held in September.
Authorities contend the candidates failed to collect enough authentic signatures to register for the election, which is seen as a dry run for the country's 2021 national parliamentary election.
Some of the opposition candidates have been jailed along with opposition politician Alexei Navalny.
At a demonstration for the same cause last week during which there were violent outbreaks, police arrested more than 1,000 people, sparking widespread global condemnation.
Russian investigators said Saturday that they had launched a criminal investigation into Navalny's alleged laundering of more than $15 million through his Anti-Corruption Foundation.
Navalny and his allies say the foundation is funded in a transparent fashion through public donations.