Vladimir Putin has secured another six-year term as Russian president, exit polls showed Sunday, paving the way for the hardline former spy to become the longest-serving Russian leader in more than 200 years.

Victory for the 71-year-old was never in doubt, with all his major opponents dead, in prison or exiled, and authorities waging an unrelenting crackdown on those who publicly oppose the Kremlin or its military offensive on Ukraine.

The government-run VTsIOM pollster projected that Putin had sailed to an easy victory with 87 percent of the vote after polls closed in Russias western-most region of Kaliningrad on the Baltic Sea.

The three-day election was marked by a surge in deadly Ukrainian bombardments, incursions into Russian territory by pro-Kyiv sabotage groups and vandalism at polling stations.

The Kremlin had cast the election as moment for Russians to throw their weight behind the full-scale military operation in Ukraine, where voting is also being staged in Russian-controlled territories.

Kyiv and its allies slammed the vote as a sham and President Volodymyr Zelensky lashed out at Putin as a dictator who was drunk from power.

There is no evil he will not commit to prolong his personal power, Zelensky said in a message on social media.

Opposition dismisses vote

Ukrainian ally Poland said the vote was not legal, free and fair, in a statement issued by the foreign ministry.

EU chief Charles Michel had sarcastically congratulated Putin on his landslide victory on the first day of polls opening on Friday.

Allies of the late Alexei Navalny - Putins most prominent rival, who died in an Arctic prison last month - had urged voters to flood polling stations at noon and spoil their ballots for a Noon Against Putin protest.

His wife, Yulia Navalnaya, was greeted by supporters with flowers and applause in Berlin. She said she had written her late husbands name on her ballot after voting at the Russian embassy.

Some voters in Moscow appeared to heed Navalnys call, telling AFP they had come to honour his memory and show their opposition in the only legal way possible.

I came to show that there are many of us, that we exist, that we are not some insignificant minority, said 19-year-old student Artem Minasyan at a polling station in central Moscow.

Leonid Volkov, a senior aide to the late opposition leader who was recently attacked in Lithuania where he fled political persecution in Russia, dismissed the results published by Moscow.

The percentages drawn for Putin have, of course, not the slightest relation to reality, Volkov, Navalnys former chief of staff wrote on social media.

Former Russian leader Dmitry Medvedev meanwhile congratulated Putin on his splendid victory long before the final results were due to be announced.

And state-run television praised how Russians and rallied with colossal support for the president as well as the unbelievable consolidation of the country behind its leader.

Tributes to Navalny

At Navalnys grave in a Moscow cemetery, AFP reporters saw spoiled ballot papers with his name scrawled across them on a pile of flowers.

Navalny had galvanised mass protests and tried to run against Putin in the 2018 election - touring Russia to drum up support - but his candidacy was rejected.

We live in a country where we will go to jail if we speak our mind. So when I come to moments like this and see a lot of people, I realise that we are not alone, said 33-year-old Regina.

There were repeated acts of protest in the first days of polling, with a spate of arrests of Russians accused of pouring dye into ballot boxes or arson attacks.

Any public dissent in Russia has been harshly punished since the start of Moscows offensive in Ukraine on February 24, 2022 and there were repeated warnings from the authorities against election protests.

The OVD-Info police monitoring group announced that at least 80 people had been detained across nearly 20 cities in Russia for protest actions linked to the elections.

A surge in Ukrainian strikes on Russia continued unabated with the Russian defence ministry reporting at least eight regions attacked overnight and on Sunday morning.

Fatal border attacks

Three airports serving the capital briefly suspended operations following the barrage, while a drone attack in the south sparked a fire at an oil refinery.

In Russias border region of Belgorod, multiple rounds of shelling killed two - a man and a 16-year-old girl - and wounded 12 more, the regions governor said Sunday.

Eight more were wounded in other bombardments later as polls were closing, he said.

The governor had already ordered the closure of shopping centres and schools in Belgorod and the surrounding area for two days because of the strikes.

In the Russian-controlled territory of Ukraines Zaporizhzhia region, where voting is also taking place, kamikaze drones set a polling station ablaze, according to the Moscow-installed authorities.

˜Difficult period

Putin, a former KGB agent, has been in power since the last day of 1999 and is set to extend his grip over the country until at least 2030.

If he completes another Kremlin term, he will have stayed in power longer than any Russian leader since Catherine the Great in the 18th century.

In a pre-election address Putin said Russia was going through a difficult period and called on the country to be united and self-confident.

A concert on Red Square is being staged on Monday to mark 10 years since Russias annexation of Ukraines Crimea peninsula - an event that is also expected to serve as a victory celebration for Putin. (AFP)