Internet giant Google has reportedly removed from its YouTube website a paid advertisement placed by supporters of Russian opposition figure Aleksei Navalny urging Russians to participate in a protest set for September 9.

Leonid Volkov, a senior Navalny aide, posted on Telegram on September 8 that Google had "complied with an illegal demand by the Russian authorities" to remove the advertisement.

Russia's Central Election Commission earlier sent a request to Google to remove the advertisement, saying it violated election laws that call for a "day of silence" on election matters ahead of voting.

Russia will hold regional and local elections on September 9.

The Prosecutor-General's Office, the Federal Antimonopoly Service, and the Roskomnadzor media regulator sent Google similar requests.

Navalny has called for nationwide protests on September 9 against a much-reviled government proposal to raise retirement ages.

Navalny's Anticorruption Foundation said the pension-reform protest has nothing to do with the elections and that the advertisement contains no election-related slogans or appeals.

Volkov noted that the advertisement was blocked even in regions where there is no voting set for September 9 and in regions where authorities have authorized the pension-reform protests.

"The corporate lawyers at Google simply don't understand that there can be situations – like the current one – and countries – like Russia – in which the demands of the authorities are often illegal," Volkov wrote.

With reporting by Novaya Gazeta and Znak