Russia's Vladimir Putin-led ruling party is on course to retain power in the country's legislative elections but with a greatly reduced share of the vote, according to the country's central election commission.
Preliminary results show Putin's United Russia party has taken 49.5 per cent of the vote, or about 30.39 million votes after Sunday's election.
That is likely to translate to 238 seats in Russia's 450-seat State Duma lower house of parliament, Vladimir Churov, chief of Russia's Central Election Commission, said on Monday.
The forecast would give the prime minister's party a relatively slim 13-seat majority in the Duma.
However, the vote was also overshadowed by opposition allegations of voting irregularities. Thousands of protesters rallied in Moscow on Monday to protest against the results of the vote, calling the poll a fraud.
Al Jazeera's Neave Barker, reporting from the rally, said police locked down the centre of the city after several hours of violent clashes between anti-government protesters and riot police backed by interior ministry forces.
He said protesters had gathered to listen to opposition leaders but many demonstrators ended up clashing with police who had hemmed in rally participants.
Although party leaders declared victory on Sunday night, the results represent a significant drop in support for United Russia compared to elections four years ago when it won over 64 per cent of the vote nationwide.
Sunday's vote was considered a crucial popularity test for Putin, Russia's prime minister and dominant political figure for more than a decade, who is seeking to return to the Russian presidency in elections in March.
"Even in difficult times, the people have declared that they believe in our potential to build a prosperous country," Putin said on Sunday night as preliminary results were released.
"It reflects the real set of moods in our country," President Dmitry Medvedev said, adding that the vote showed "democracy in action".
While United Russia gained almost half of votes, support for opposition parties was split with the Communist Party coming in second with 19 per cent of the vote, the populist A Just Russia group polling almost 13 per cent and the ultra-nationalist Liberal Democratic Party almost 12 per cent, with 96 per cent of the results counted.
The country's Central Election Commission said the remaining four per cent could take at least five more days to count, as results were coming from remote regions and from abroad.
About 60 per cent of Russia's 110 million registered voters cast ballots, down from 64 per cent four years ago.
Our correspondent said that in the past low voter turnout suggested "that people are relatively apathetic in terms of whether or not their vote is actually going to make a difference to the political makeup of the country".
"But I think, this time around with the results reflecting losses for United Russia, it does suggest that people are making a concerted effort to change the country's political landscape," he said.
The drop in United Russia's popularity appeared to reflect a sense of disenchantment with Putin's authoritarian course, the party's failure to address corruption and the gap between ordinary Russians and the super-rich.
"There is quite a subtle shift in the political mood here in Russia," Andrew Osborn, Moscow correspondent for the UK's Daily Telegraph, told Al Jazeera. "This is the first sign things might be changing. People are not willing to put up with the total dominance of one party anymore."
Communist Party leaders and other parties denounced the elections after polls closed, complaining of irregularities aimed at boosting United Russia's vote count, including intimidation of voters and other accusations of unprecedented dirty tricks by the authorities.
Communist leader Gennady Zyuganov said his party monitors thwarted an attempt to stuff a ballot box at a Moscow polling station where they found 300 ballots already in the box before the start of the vote.
He said incidents of ballot-stuffing were reported at several other stations in Moscow, Rostov-on-Don and other areas.
In Vladivostok in the east, voters complained to police that United Russia was offering free food in exchange for promises to vote for the party.
Our correspondent said that Golos, the country's only independent election observer, had reported that more than 5,000 irregularities had been recorded, mostly related to people being pressured to vote for United Russia.
Meanwhile, international observers led by the Organisation for Security and Co-operation in Europe (OSCE) said on Monday that Russia's parliamentary polls were marred by frequent procedural violations including ballot stuffing.
Sunday's polls "were characterised by frequent procedural violations and instances of apparent manipulation, including serious indications of ballot box stuffing", the security body said after observing 115 polling stations.
The White House on Monday expressed concern about reports of voter irregularities, including what it said were reports of "a lack of fairness in the process, attempts to stuff ballot boxes, and the manipulation of voter lists.
Only seven parties had been allowed to field candidates for parliament this year, while the most vocal opposition groups have been denied registration and barred from campaigning.