Russia began three days of voting Friday in a presidential election that is all but certain to extend President Vladimir Putin’s rule for six more years after he stifled dissent.

At least half a dozen cases of vandalism at polling stations were reported, including a firebombing and several people pouring green liquid into ballot boxes -- an apparent nod to the late opposition leader Alexei Navalny, who in 2017 was attacked by an assailant splashing green disinfectant in his face.

Voting is taking place through Sunday at polling stations across the vast country’s 11 time zones, in illegally annexed regions of Ukraine and online. Putin cast his ballot online, according to the Kremlin.

The election comes against the backdrop of a ruthless crackdown that has crippled independent media and prominent rights groups and given Putin full control of the political system.

It also comes as Moscow’s war in Ukraine enters its third year. Russia has the advantage on the battlefield, where it is making small, if slow, gains. A Russian missile strike on the port city of Odesa killed at least 14 people on Friday, local officials said.

Ukraine, meanwhile, has made Moscow look vulnerable behind the front line with long-range drone attacks deep inside Russia and high-tech drone assaults that put its Black Sea fleet on the defensive.

Russian regions bordering Ukraine reported a spike in shelling and repeated attacks this week by Ukrainian forces, which Putin described Friday as an attempt to frighten residents and derail the vote.

“Those enemy strikes haven’t been and won’t be left unpunished,” he vowed at a meeting of his Security Council.

“I'm sure that our people, the people of Russia, will respond to that with even greater cohesion,” Putin said. "Whom did they decide to scare? The Russian people? It has never happened and it will never happen."

By the time polls closed Friday night at Russia's westernmost region of Kaliningrad, more than a third of the country's eligible voters had cast ballots in person and online, according to the Central Election Commission. Online voting, which began Friday morning, is available around the clock in Moscow and 28 other regions until 8 p.m. local time Sunday.

Officials said voting proceeded in an orderly fashion, but in St. Petersburg, a woman threw a Molotov cocktail on the roof of a school that houses a polling station, local news media reported. The deputy head of the Russian Central Election Commission said people poured green liquid into ballot boxes in five places, including Moscow.

News sites also reported on the Telegram messaging channel that a woman in Moscow set fire to a voting booth. Such acts are incredibly risky since interfering with elections is punishable by up to five years in prison.

The election holds little suspense since Putin, 71, is running for his fifth term virtually unchallenged. His political opponents are either in jail or in exile; Navalny, the fiercest of them, died in an Arctic penal colony last month. The three other candidates on the ballot are low-profile politicians from token opposition parties that support the Kremlin’s line.

Observers have little to no expectation the election will be free and fair.

European Council President Charles Michel mordantly commented Friday on the vote’s preordained nature. “Would like to congratulate Vladimir Putin on his landslide victory in the elections starting today. No opposition. No freedom. No choice,” he wrote on X, formerly Twitter.

Beyond the fact that voters have few options, the possibilities for independent monitoring are very limited.

No significant international observers were present. The Organization for Security and Cooperation Europe’s monitors were not invited, and only registered candidates or state-backed advisory bodies can assign observers to polling stations, decreasing the likelihood of independent watchdogs. With balloting over three days in nearly 100,000 polling stations, any true oversight is difficult anyway.

“The elections in Russia as a whole are a sham. The Kremlin controls who’s on the ballot. The Kremlin controls how they can campaign. To say nothing of being able to control every aspect of the voting and the vote-counting process,” said Sam Greene, director for Democratic Resilience at the Center for European Policy Analysis in Washington.

Ukraine and the West have also condemned Russia for holding the vote in Ukrainian regions that Moscow’s forces have seized and occupied.