Ruling party United Russia won Sunday's parliamentary election in a poll marred by hacker attacks on opposition websites and the arrests of dozens of people protesting alleged vote fraud, dpa reported.
United Russia, which is headed by President Dmitry Medvedev, had 49 per cent of the popular vote with 39 per cent of all ballots counted, election officials said.
That is down on previous electoral showings for the party and, if further ballot counts were to go heavily against the ruling party, possibly threatening United Russia's past unchallenged control of the national legislature, the Duma.
Russian President Dmitry Medvedev called the results a clear success for United Russia, and said he was confident the party would retain a clear Duma majority.
"These elections have produced a result that shows the real political balance in the country," he said. "Other people may not like it, but the democratic process has functioned, ... and Russia will get a capable parliament."
United Russia "probably got around 50 per cent" of the votes - enough to maintain a majority in parliament, Medvedev said, in comments made from the party's Moscow headquarters and aired by the NTV television channel.
Official counts made public at 11 pm in Moscow (1900 GMT) put the opposition Communist party on track to receive almost 20 per cent of ballots. Running neck-and-neck, the centrist Fair Russia was at 13.07 per cent and the ultra-right Liberal Democrats 12.66 per cent.
Exit polls roughly matched the partial official counts and predicted United Russia would, narrowly, retain its parliament majority.
The Communists appeared to be the election's big winners, having nearly doubled their 11 per cent support from 2007.
Communist Party leader Gennady Zyuganov, in television statements, said accurate ballot counts were critical to prevent vote fraud.
"We don't want any one else's votes, but we have no intention of giving ours away either," Zyuganov told Rossiya television. "There are a great many problems facing the country."
He avoided answering a Rossiya TV question whether the Communists would consider participating in any coalition government with United Russia.
An estimate of parliament seat division aired by NTV shortly after polls closed predicted United Russia would receive 237 seats, the Communists 95 seats, Fair Russia 71 seats and the Liberal Democrats 47 seats - sufficient to continue the unchallenged control of the 450-seat legislature held by United Russia since the early 2000s.
Central Election Commission Chairman Vladimir Churkin in statements throughout voting day said the election ran smoothly, making no direct comment on either cyber-attacks against several opposition websites or the arrests of 130 protesters over the course of the day.
"We appear to be on track to have turnout better than in the last parliamentary election. ... The voting is crystal clear and clean," Central Election Commission Chairman Vladimir Churkin told RTR television.
Turnout was slightly above 50 per cent, according to official data made public Sunday afternoon, when many polling sites were still open.
In Moscow, police arrested some 70 protesters on Sunday afternoon for handing out pamphlets against what they deemed "a dirty vote." Some bystanders shouted "shame" as the mostly young demonstrators were manhandled by police.
Security forces broke up a similar protest in St Petersburg, where some 50 demonstrators were arrested. More than 333,000 police and army soldiers were mobilized for the election nationwide.
Independent websites giving information sometimes critical of the government appeared to be the target for a powerful hacker attack within hours of polls opening.
For example, the website of Golos.ru, the last remaining independent election-monitoring group based in Russia, was shut down at approximately 6 am Moscow time (0200 GMT). The group is partially financed by the European Commission and in recent weeks had recorded thousands of election law violations, most of which aimed to skew the vote to favour the United Russia party.
Similarly targeted were the websites of Ekho Moskvy, a radio station critical of the Kremlin, and publicpost.ru, a site that publishes non-mainstream news reports from across the vast country.
Both had offered links to a golos.ru interactive map with detailed data on the precise locations and types of election law violations, and those responsible.
Putin in recent comments called Russians working for vote monitoring groups linked to international agencies "Judases."
Election reports on government TV channels showed up-beat images of apparently satisfied voters and cosmonauts casting ballots from space.
Most programming throughout the day was devoted to comedies or patriotic films. State-run media made no reports about either the protester arrests or the website shutdowns.