London (CNN Business) Google has been warned by Russia's state communications regulator to stop "advertising" protests on YouTube ahead of local elections in Moscow.

The watchdog, called Roskomnadzor, said in a letter to Google on Sunday that it considered advertisements and push notifications that publicize protests as "interference" in its domestic politics.

Tens of thousands of people rallied in Moscow over the weekend calling for fair local elections. More than 200 people were detained, according to OVD-Info, a group that monitors police.

Protesters have gathered in Moscow for five weekends in a row demanding that authorities allow independent candidates to take part in city's upcoming local elections. Some protests have been sanctioned by authorities.

While it's not clear which specific accounts or channels Roskomnadzor was referring to, several YouTube accounts broadcast the protests live.

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