He said the decree, which bans all public demonstrations and other events, was submitted to parliament, which will consider it within the next 48 hours.
Konstantin Gamsakhurdia, the son of Georgia's ex-president, Zviad Gamsakhurdia, and an opposition leader was detained, an opposition party leader said on Wednesday.
Georgian Rustavi-2 channel also reported on Wednesday that Georgian police detained two opposition leaders, and the chief of the news service at the Imedi television company, the police though, have denied arresting the Imedi journalist.
"Moscow regards the latest idiocy by Georgian authorities as political irresponsible provocation. An appropriate response will be made, and Russia will remain true to its commitments regarding assisting in the settlement of the Georgian-Abkhazian and Georgian-Ossetian conflicts and the protection of Russian nationals living there," the Russian Foreign Ministry statement said.
The ministry said, "The most important thing is that assessments by certain public figures in Tbilisi for using force to settle conflicts do not materialize."
Russia's Foreign Ministry has urged all those who have any influence on Tbilisi to caution the Georgian leadership against taking "destructive steps."
Referring to the Georgian president's accusations that Russia's special services were behind recent events in Tbilisi, the ministry said such steps were fraught with unpredictable consequences. Sakaashvili's comments were made earlier on Wednesday during an address to the nation on Georgian TV.
Opposition supporters have been demonstrating in Tbilisi for the past six days, demanding President Mikheil Saakashvili's resignation and early elections. Riot police used water cannons, rubber bullets and tear gas on Wednesday to disperse protesters.