MOSCOW -- President Vladimir Putin's United Russia party looks set for another big win in the country's parliamentary elections, despite a drop in support, BBC reported.

The party claimed victory a few hours after the polls closed on Sunday evening.

Putin's most vocal critics were barred from running in the election, and candidates who were allowed to stand were heavily vetted.

There have been numerous allegations of ballot stuffing and forced voting.

But Russia's electoral commission rejected claims of widespread irregularities.

Initial results showed that with 80% of votes counted, United Russia had won nearly 50%, followed by the Communist Party with about 20 percent.

A senior United Russia official, Andrei Turchak, said his party would win more than 300 of the 450 seats in the State Duma.

The partial results show that despite Mr Putin's party easily retaining its majority in parliament, it did lose some ground. In 2016, the party won 54 percent of the vote.

The Communists, who broadly support Putin's initiatives in the parliament, saw their support grow by 8%. But their leader, Gennady Zyuganov, has alleged widespread violations, including ballot-stuffing, according to the Associated Press news agency.

Concerns over living standards and allegations of corruption from jailed Kremlin critic Alexei Navalny have likely affected support for Mr Putin's party.

But he remains popular with many Russians who credit him with standing up to the West and restoring national pride.

Many opposition politicians and activists had been barred from the ballot. First and foremost, supporters of the jailed opposition leader Alexei Navalny.

The coronavirus pandemic was the official reason for spreading voting over three days. But critics say the extended poll lacks transparency and is open to abuse.

Reports of voting irregularities have been coming in from across Russia.

The head of the election commission, however, said the criticism was part of "a planned, deliberate campaign, well financed from abroad". It's a sign of things to come. This is how Moscow will react to any international criticism of the election: by pointing a finger at the West and claiming it's all part of a foreign conspiracy to discredit Russia.

As of Sunday evening, independent vote monitoring group Golos -- which the Russian authorities have branded "a foreign agent" -- said it had tracked more than 4,500 reports of voting violations.

Russia's interior ministry meanwhile told reporters that it had not registered any "significant violations".

During the election, long queues were seen outside some polling stations on videos published on social media.

Interfax news agency reported that this was especially the case outside police stations. The Kremlin spokesman rejected claims that it was an indication of people being put under pressure to vote.

But Golos said it had received "numerous messages" from people who said they were being forced by their employers to vote, as well as allegations of electoral fraud.

In parts of east Ukraine controlled by Russian-backed separatists, residents with Russian citizenship were allowed to vote, with some crossing the border to visit Russian polling stations.

There has also been anger after a Smart Voting app devised by jailed Russian opposition leader Alexei Navalny was removed from Apple and Google stores on the day that Russians started voting.

Russian authorities had threatened the two companies with big fines if they refused to drop the app, which told users who could unseat ruling party candidates.

Navalny ally Leonid Volkov accused the tech giants of having "caved under the Kremlin's blackmail".

One Moscow pensioner who gave his name only as Anatoly told Reuters news agency he voted for the ruling party as he appreciated Putin's efforts to restore Russia's influence on the world stage.

"Countries like the United States and Britain more or less respect us now like they respected the Soviet Union in the 1960s and 70s... The Anglo-Saxons only understand the language of force," he said.

But there was also widespread indifference.

"I don't see the point in voting," said one Moscow hairdresser who gave her name as Irina. "It's all been decided for us anyway." -- Agencies