MOSCOW -- Nearly 700 people, including a prominent opposition activist, were detained by riot police in Moscow on August 3 after authorities warned they would take “all necessary measures” to stop the unsanctioned rally.
A week after police detained more than 1,300 people at a similar protest in the Russian capital, hundreds of OMON riot police were deployed ahead of the planned protest to demand free elections in Moscow.
The independent political watchdog OVD-Info reported that at least 685 people had been detained. City police put the number at 600.
The prominent Russian opposition activist Lyubov Sobol was taken away by police as she left her political headquarters.
Sobol, who is on hunger strike and a key organizer of the current wave of protests, was taken from a taxi as she tried to make her way to the protest and driven off in a police van.
"On what grounds are you detaining me?" Sobol repeated as police bundled her into the vehicle.
WATCH: Russian Police Detain Opposition Activist Sobol
Moscow has witnessed protests since authorities there in July banned multiple opposition candidates -- including Sobol -- from running in a municipal election scheduled for September.
More than 1,300 demonstrators were detained by police at the last rally in the city on July 27.
Several would-be candidates to the Moscow City Duma have also faced harassment, including arrests and home searches.
WATCH: Live stream of the protests from Current Time
The opposition, many allied with jailed opposition politician Aleksei Navalny, say local officials want to keep them out, fearing they will beat pro-Kremlin candidates. Local election officials say the rejected candidates submitted invalid signatures among the required 5,500 to get on the ballot.
The Moscow City Duma, which has 45 seats, is responsible for a $43 billion municipal budget and is now controlled by the pro-Kremlin United Russia party. All of its seats, which have a five-year-term, are up for grabs in the September 8 vote.
"This is the last chance for us to try to say something," Viktor Shenderovich, a prominent political satirist and now vocal voice for the opposition, told our correspondent. "The government is heading towards a head-on, physical collision with us, towards a catastrophic escalation.”
Shenderovich, who was among the more than 1,300 people detained at the July 27 protest, said he feared the same fate on August 3.
“Of course I’m afraid. Just like everyone who came out today,” he said, looking around at the huge crowd that had formed to hear him speak. “You simply can’t get used to this violence.”
Demonstrators were aiming to hold a march along the Boulevard Ring that skirts central Moscow but helmeted OMON riot police were deployed in large numbers, erecting metal barricades, and blocking off areas of central Moscow, making it nearly impossible for demonstrators to gather.
“Dear citizens, law enforcement is working to ensure your safety! Among them are military servicemen! These are your own sons!” a loudspeaker blared in central Moscow as a police helicopter hovered overhead.
Moscow authorities earlier urged businesses in central Moscow either to shut for the day or take additional security measures.
The Moscow city prosecutors’ office warned on August 2 that police will "take all necessary measures to stop provocations, riots, and any actions entailing a violation of public security."
"Any attempts to conduct mass, unauthorized public events in the city of Moscow on August 3, 2019, are a direct violation of the law," the prosecutors’ office warned.
“So far the Russian government is unable to organize fair elections,” Sergei Parkhomenko, a Russian correspondent and commentator, told our correspondent.
“I wasn’t surprised about the crackdown on protesters last week,” he said. “The government has no other instrument to use, except force."
Authorities carried out a new round of detentions and home searches before the August 3 protest and opened criminal proceedings for what they term mass civil unrest, an offence which carries a penalty of up to 15 years in jail.
At least eight of Sobol's allies, including Navalny, are in jail for breaking tough protest laws.
Russia's Investigative Committee announced on August 3 it was opening a criminal case against Navalny’s Foundation for Fighting Corruption. The committee said the organization was suspected of receiving funding that had been criminally acquired.
Navalny and his allies say the foundation is transparently financed from public donations.
Meanwhile, a rally in support of the Moscow protests was held on August 3 in St. Petersburg, drawing several thousand people, the local news site Fontanka.ru reported.