Five officers were detained in Georgia earlier this week on suspicions of spying - an act described by Moscow as a provocation. One of the officers was later released, while the other four have been officially charged with espionage
Lawyer Andranik Saribekov said the accused would appeal the decision.
He said the case should be submitted to a court within the two-months period, adding that prosecutors could prolong the term of custody or submit the case later.
The Russian Foreign Ministry dismissed the spying allegations Wednesday night as unsubstantiated, and senior officials, including Defense Minster Sergei Ivanov and Foreign Minister Sergei Lavrov, have led the charge of vigorous criticism of Tbilisi's decision to arrest the officers.
"Gangsterism in Georgia has taken on a state scale," Ivanov said Thursday.
Ivanov also said seven other Russian servicemen - a junior officer and six soldiers - were subjected to violence when their car was stopped in the western city of Batumi Wednesday night.
Andrei Popov, the commander of the Russian troops in the Caucasus, said Friday Georgia has returned weapons, ammunition and a car confiscated from the Russian servicemen in Batumi.
He also said a cordon around the Russian contingent's headquarters in Tbilisi has not yet been lifted, as the Georgian side keeps demanding the surrender of another Russian officer wanted by Georgia, Lieutenant Colonel Konstantin Pichugin.
Russia's Ambassador to Georgia, Vyacheslav Kovalenko, who has been recalled to Moscow for consultations, said a furor over four Russians charged in Tbilisi with spying was an insult, and vowed to return to the Caucasus state only when the officers have been released.