Legislation imposing tougher sanctions on illegal immigrants came into force on Friday, but the new rules will only apply to Moscow, the Moscow region, St. Petersburg and the Leningradsky region.
Illegal migrants detained in these regions can now be fined from 5,000 to 7,000 rubles ($152 to $213), and deportation is now mandatory according to the amendment, Kommersant reported.
Employers found to be hiring illegal immigrants will have to pay between 50,000 to 75,000 ruble, while legal entities can be fined 1.5 million rubles and have their activities suspended for a period of 14 to 90 days.
Russia's remaining regions will stick with the previous system that stipulates fines of up to 5,000 rubles, without mandatory deportation.
The introduction of the new sanctions coincides with a wider campaign to combat illegal immigration that has been marked by sweeping police raids on the country's markets.
The campaign was sparked by a fight at the Matveyevsky market on July 27 between the police and the relatives of rape suspect Magomed Magomedov. The fight left one police officer in hospital with a severe head injury.
About 600 illegal immigrants are being held at a tented camp in Moscow's Golyanovo district and the authorities are finding it difficult to process their details.
Nine out of ten immigrants at the camp have given the authorities false information about themselves, said Olga Kirillova, the head of the Federal Migration Service's Moscow office.
"At the current moment we cannot positively identify all individuals contained in the camp," Kirillova said, adding that less than 50 people had been identified and were ready to leave.
She said that the migration authorities were having difficulty transliterating the names of the Vietnamese immigrants into Russian. The Federal Migration Service has asked the Vietnamese Embassy to provide assistance, she said.
Kirillova said that the camp will be wound up soon, Interfax reported Friday. She said that about a third of those being held will be deported as early as next week, depending on the availability of transport.