The election, marred by numerous reports of violations, lacked significant opposition presence after authorities declared organisations linked to imprisoned Alexey Navalny, the Kremlin’s most prominent foe, to be extremist.
The ruling United Russia party, which supports President Vladimir Putin, is on course to win a three-day parliamentary election, initial results and an exit poll showed.
With just 9 percent of ballots counted nationwide, the Central Election Commission said United Russia had won 38.57 percent of the vote.
Separately, an exit poll conducted by INSOMAR and published by Russia's RIA news agency predicted United Russia would win just over 45 percent of the vote.
The party won just over 54 percent of the vote in 2016, the last time a parliamentary election was held.
It has since faced a slump in its popularity due to malaise over years of faltering living standards.
Initial results showed the Communist Party finishing in second place with 25.17 percent of the vote, followed by the nationalist LDPR party with 9.6 percent.
Crackdown on opposition
The vote came in the wake of a clampdown this year that saw Putin's best-known domestic foe Alexey Navalny jailed and his organisations banned as "extremist".
In the lead-up to the vote, all of Navalny's top allies were arrested or fled the country, with anyone associated with his groups kept from running.
Authorities also took drastic measures to deter Navalny's "Smart Voting" campaign, which guided voters on which candidates to support to have the best hope of denying Kremlin-aligned politicians a seat.
In this election most of its voting list consisted of Communist Party candidates.
The campaign's website was shut down and on Friday Apple and Google removed the "Smart Voting" app from their stores, causing an uproar among the opposition who accused them of giving in to Kremlin "blackmail".
Sources familiar with Google and Apple's decision said the move was taken under pressure from Russian authorities, including threats to arrest the tech giants' local staff.
By late Friday, the popular Telegram messenger had also removed Navalny's "Smart Voting" bot, and by Sunday Google Docs and YouTube videos containing the lists of the recommended candidates had also been blocked.
Navalny's team promptly made new Google Docs and YouTube videos with the lists of candidates, and in a final pitch to voters from behind bars, the Kremlin critic wrote on Instagram: "Today is a day when your voice truly matters."
Reports of voting violations
Turnout was at 45 percent according to the latest figures released by the election commission at 1500 GMT.
Russian social media meanwhile was inundated with reports of ballot stuffing and military servicemen patrolling pol ling stations.
Critics also pointed to online voting, new limits on independent election observers and the polls being spread over three days – a move officials said was to reduce coronavirus risks – as presenting opportunities for fraud.
As of Sunday evening, independent election monitor Golos -–which authorities branded a "foreign agent" ahead of the polls – had tracked over 4,500 reports of voting violations.
Russia's interior ministry, however, told news agencies on Sunday evening that it had not registered any "significant violations".
Going into the lower house State Duma vote, United Russia party was polling at historic lows.