A Russian law that criminalizes undeclared dual citizenship for Russian citizens has come into force.
The law was adopted by the State Duma in May and signed by President Vladimir Putin in July.
It imposes a fine of up about $5,800 or 400 hours of community service on Russians who fail to inform the Russian authorities that they have obtained citizenship in another country.
For residents of Crimea -- the Ukrainian region that joined Russia in March -- Russian authorities will begin enforcing the law on January 1, 2015.
The procedure necessary for declaring dual citizenship remains unclear.
Russian lawmakers estimated in 2010 that around 1.6 million Russian citizens permanently live abroad, more than half of them in the European Union, Israel, and the United States.
Since the Russian annexation of Crimea, all the residents of the region were forced to take Russian citizenship, amid great amount of Crimeans wished to remain citizens of Ukraine.
Russian passports are given to Crimeans not by the Ministry of Internal Affairs, but by the Federal Migration Service of Russia, that means they are valid on the territory of Russia Federation only.