Russia’s Central Election Commission has reported more than 50% turnout in the presidential election which President Vladimir Putin is certain to win another six years in office overwhelmingly.
Mr Putin faces seven challengers but none poses a serious threat.
The commission said 51.9% of Russia’s nearly 111 million eligible voters have cast ballots.
Election commission chief Ella Pamfilova also said officials around the country are taking quick measures in response to claims of violations.
Independent election observers and activists have alleged numerous incidents of ballot stuffing and other irregularities in Sunday’s vote.
The commission said it is quickly responding to claims of violations in the vote.
Commission chief Ella Pamfilova said: “We are immediately reacting to all claims, no matter where they come from.”
Election officials have responded similarly to allegations of ballot stuffing in the town of Lyubertsy just outside Moscow and the far eastern town of Artyom and have been looking into several other complaints.
In Artyom, a man tossed several ballots into the box, according to Tatiana Gladkhikh, the head of the regional election commission. She said the ballot box was sealed and the man was arrested.
Mr Navalny was barred from the campaign because of a criminal conviction widely seen as politically motivated. He urged his supporters not to vote because of the absence of any real competition in Sunday’s election.
Mr Navalny said in a video posted on YouTube that “on election day, one should usually want to say ‘I voted,’ but in fact I’m here to say that I didn’t go to vote.”
He criticised the seven contenders challenging Mr Putin for failing to protest against ballot stuffing and other irregularities tainting the election, saying on his blog that “such candidates aren’t worthy of your vote.”
Russian opposition presidential candidate Ksenia Sobchak cast her ballot and urged Vladimir Putin’s critics to vote instead of boycotting.
Ms Sobchak, a 36-year-old former TV star, told reporters in Moscow that the higher the support for Mr Putin in the vote, “the tougher the system” Russians will face in his new term.
Ms Sobchak urged Mr Putin’s critics to “come together”, and argued against the boycott called for by opposition leader Alexei Navalny, who is barred from running.
She said “every extra percentage point” for Mr Putin is a result of those who refuse or do not bother to vote.
Russia’s central election commission says its website was the target of an unsuccessful hacking attempt during Sunday’s presidential election.
Commission chairwoman Ella Pamfilova said it was a DDoS, or distributed denial of service, attempt tracked to computers in 15 countries, without naming them. Such attacks are very common.
She said efforts to disrupt the site occurred when voters in Russia’s far east were already casting ballots, but they were deterred by Russian authorities.
As US authorities investigate alleged Russian hacking and other interference in President Donald Trump’s 2016 election, Russian authorities claimed that foreign powers are seeking to interfere in Sunday’s vote.
Mr Putin hopes for high turnout despite widespread apathy.
Some 145,000 observers are monitoring the voting in the world’s largest country, including 1,500 foreigners and representatives from Mr Navalny’s political movement.
Mr Navalny accused Ms Sobchak of discrediting the opposition by joining the race.
He told her a YouTube broadcast that she was a “parody of a liberal candidate” and her involvement in the campaign helped the Kremlin cast the opposition in a negative light, and rejected her proposal to join forces.
Ms Sobchak, who is the daughter of Putin’s one-time patron, rejected the accusations, saying she has used the race to champion liberal ideas, attract public attention to some of the most acute issues and encourage important regional projects.
Critics have accused Ms Sobchak of helping Putin create a semblance of competition in the vote he is set to easily win. She has denied collusion with the Kremlin.