(Reuters) - Russian citizens in Latvia cast ballots in their home country's presidential election on Sunday, while opponents of President Vladimir Putin rallied in front of the embassy in Riga in a peaceful "noon against Putin" protest.

While a sizeable number of people who arrived recently in the country were likely to cast a vote against Putin or take part in the protest, more longtime Russian residents were more reticent about expressing their views.

At the beginning of 2023, there were some 37,906 Russian citizens in Latvia, a country of only 1.88 million that borders Russia and is strongly opposed to Putin since Moscow's invasion of Ukraine.

Organizers of the protest in Riga said around 100 campaigners against Moscow's war and supporters of late Russian opposition leader Alexei Navalny gathered in front of the embassy by noon (1000 GMT). The gathering echoed similar "noon against Putin" protests that took place in some parts of Russia and in foreign capitals.

"We already know results of the election but it is a big hope those are the last such elections," said one of the organizers, Marina Fomina.

Some elderly voters interviewed by Reuters outside the polling station in Riga, at Russia's embassy in the city, said it was their civic duty to vote, but did not reveal which candidate they would support.

Putin, 71 and in power for more than two decades, is certain to win another six-year term in the election, where voting was drawing to a close on Sunday evening.

Vladimir, a permanent resident in Latvia who gave only his first name, said he came to came to cast a blank ballot. "I don't want war, I don't want things like in Ukraine," he added.

Andrei, 28, voting in the Russian election for the first time, said he would vote against Putin even though the results is "probably obvious" as this might be the only way to oppose the war.

Kirill Martynov, editor in chief of Novaya Gazeta Europe, an independent Russian media outlet founded in Riga in April 2022 after the introduction of wartime censorship in Russia, said he planned to oppose this elections by spoiling the ballot.

Latvian police and border guards were checking voters' documents outside the polling station. The Latvian State Police chief, Armands Ruks, said the controls were to ensure Russian citizens taking part in the voting did not break the law.

By noon, 351 people were checked at the entrance of the Russian embassy in Riga and 14 were found with expired residency permits, the State Police told local media.

One voter said she was afraid to speak to the media or give her name for fear her residence permit in Latvia might not be extended.

The Russian embassy condemned cases of confiscation of Latvian identity documents from Russian voters, with some citizens now required to appear at the migration service to receive an order to leave.

(Reporting by Dagmarah Mackos in Riga and Lina Golovnya in Gdansk; Editing by Frances Kerry)