MOSCOW (DPA) - US internet companies Google and Facebook on Monday (Sept 9) rejected Moscow's allegations that they had interfered in Russian elections by running political ads during the voting day.

The search engine Google and the social network Facebook said in separate statements that it was the advertisers who were responsible in the matter, Russian news agency Interfax reported.

"We support responsible political advertising and expect that it must comply with local legislative requirements," Google said.

Facebook expressed a similar sentiment, adding: "If we receive notice that an advertisement violates local legislation, we examine it and take appropriate measures."

Russia's federal communications watchdog had on Sunday accused the companies of violating legislation prohibiting political advertising during elections.

"Such actions can be regarded as interference in Russia's sovereign affairs and obstruction of democratic elections," the watchdog Roskomnadzor said in a statement.

Russia held municipal and regional elections throughout the country on Sunday that had been marked by a wave of pro-opposition protests in the run-up to the vote.

Russian senior officials have asserted that foreign powers have been supporting the protesters.

A senior lawmaker threatened last week to expel German state broadcaster Deutsche Welle as it refused to attend a parliamentary hearing on an allegation that its coverage was interfering in Russian affairs.

A Deutsche Welle reporter was briefly detained while covering a Russian political opposition protest in Moscow in July.