MOSCOW — Russians on Sunday voted to elect governors and mayors in the first such polls since President Vladimir Putin's return to the Kremlin as observers complained of numerous violations.

Voters went to the polls to elect different layers of local and regional government in almost all the country's regions, with the largest cities of Moscow and Saint Petersburg among the few not to vote.

Most local and regional governments in Russia are dominated by the ruling United Russia party, a situation that was not expected to change in the polls.

Observers and opposition politicians standing for election reported numerous violations including groups of people voting multiple times and the stuffing of ballot boxes.

Russia's Golos vote monitor on Sunday evening showed more than 800 reported violations on its map of complaints submitted online.

The Golos map was criticised as a "provocation" by the deputy chairman of the Central Electoral Commission, Leonid Ivlev, in televised comments as he said the commission had received only 55 complaints.

Co-chairman of the liberal RPR-Parnas party, Vladimir Ryzhkov, who was standing for the legislature of the Siberian city of Barnaul, listed on Facebook the licence plates of cars he alleged were ferrying round a "carousel" of repeat voters.

Central Electoral Commission chairman Vladimir Churov, a hate figure to opposition activists because of vote-rigging in December's parliamentary polls, responded by ordering a check in Barnaul.

Yet senior United Russia party official Sergei Neverov in comments to the party's website accused the opposition of "a campaign to discredit the vote" in the city.

"The people, as the first results show, are voting for our candidates," he said.

In the western Bryansk region, where a Communist candidate for governor was standing against a low-rated United Russia candidate, the Communists complained of "mass violations" including voters filling in their ballots in front of electoral officials.

Eco campaigner and anti-Putin protest leader Yevgenia Chirikova who was standing for mayor in the Moscow satellite town of Khimki reported a string of violations via Twitter.

After hearing that observers at one polling station were being ordered to stay sitting down rather than walking round freely to view the vote, Chirikova stormed over and fiercely ordered the organisers to halt the violation.

"Observers at polling station 3018 are complaining of threats of physical harm... We're heading over," she wrote on Twitter later.

The businesswoman has led a campaign against road construction outside the town around 20 kilometres (12 miles) from Moscow, where she is fighting a candidate backed by United Russia.

In a new development, the polls allowed voters in five different regions across the country to elect governors for the first time since Putin abolished such direct elections in 2004.

These polls were attracting the highest turnouts by Sunday evening.

"The most important point of the single day of voting is that after an eight-year break we are holding elections for the highest officials of regions: elections for governors," said Ivlev in televised comments.

Putin introduced presidential appointment of governors after the deadly Beslan school siege in 2004, calling it a necessary measure to prevent separatism and crime.

But the move was widely criticised by the opposition and Putin's successor as president Dmitry Medvedev signed a law reviving direct elections for governors shortly before leaving office this May.

Ruling governors from United Russia were expected to win easily in most regions.

The races were seen as unpredictable only in the Bryansk region and the central Ryazan region where United Russia candidates had low ratings and were fighting off strong opponents from the Communist Party.