President Vladimir Putin was poised to tighten his grip on power yesterday in a Russian election that is certain to deliver him a landslide victory, though thousands of opponents staged a symbolic noon protest at polling stations.

Putin, who rose to power in 1999, is set to win a new six-year term that would enable him to overtake Josef Stalin and become Russia's longest-serving leader for more than 200 years.

The election comes just over two years since Putin triggered the deadliest European conflict since World War Two by ordering the invasion of Ukraine. He casts it as a "special military operation".

War has hung over the three-day election: Ukraine has repeatedly attacked oil refineries in Russia, shelled Russian regions and sought to pierce Russian borders with proxy forces - a move Putin said would not be left unpunished.

While Putin's re-election is not in doubt given his control over Russia and the absence of any real challengers, the former KGB spy wants to show that he has the overwhelming support of Russians. Several hours before polls were due to close at 1800 GMT, the nationwide turnout surpassed 2018 levels of 67.5 percent.

Supporters of Alexei Navalny, who died in an Arctic prison last month, had called on Russians to come out at a "Noon against Putin" protest to show their dissent against a leader they cast as a corrupt autocrat.

There was no independent tally of how many of Russia's 114 million voters took part in the opposition demonstrations, amid extremely tight security involving tens of thousands of police and security officials.

Reuters journalists saw an increase in the flow of voters, especially younger people, at noon at some polling stations in Moscow, St Petersburg and Yekaterinburg, with queues of several hundred people and even thousands.