Facebook representatives announced this week that it now counts 5 million active users in Russia, reported news agency RIA Novosti.

That figure, however, represents a mere one Internet user out of ten, and Facebook still lags behind Russia’s social networking behemoths Vkontakte (23 million unique users in February 2011, according to TNS), MoiMir (20 million), and Odnoklassniki.ru (18 million).

Vkontakte.ru (“In contact” in Russian) was designed as a Facebook clone when it was launched in 2006, but important differences now distinguish the two sites.

“In Russia, our audience is indeed particular,” Angela Zaeh, Facebook’s development director for Eastern Europe, told RIA Novosti. “We are slowly starting to attract a broader range of users, and our main tool for doing this is the users themselves, who are inviting each other to Facebook.”

Zeh says that Facebook’s next objective for its Russian site is to amass 10 million users, after which Facebook can consider itself to be a truly significant player on the local market.

Facebook presented a Russian version of its site in 2008 and began launching active marketing campaigns in 2010. Over the past few months, it has offered Russian users more localized features, such as integration with both LiveJournal, the third largest blogging platform for Russian speakers in terms of traffic, and with QIP, a popular messaging system.

The company is also talking with mobile phone makers about embedding a Facebook application on handsets sold in Russia.