Russian President Vladimir Putin has signed a decree that classifies military losses during special operations in peacetime.
The edict, on amendments to a 1995 presidential decree on state secrets, was published on Russia's official legislative website on May 28.
Previously, information on Russian military losses was classified as a state secret only during wartime.
Now, any information on individuals of interest to Russian intelligence, counterintelligence, and operative services as possible collaborators is also classified as a state secret.
Previously, that status was extended only to information about actual collaborators.
The amendments come amid accusations that Russian troops are involved in fighting between Ukrainian forces and pro-Russian separatists in eastern Ukraine, which Moscow denies.
Kremlin spokesman Dmitry Peskov said the amendments are “not linked with Ukraine.”
Asked whether they could mean that Putin is planning to launch special operations in Ukraine, Peskov said, "No, he is not
Activists in Russia claim that the bodies of Russian troops have been brought secretly from Ukraine to Russia for burial.
The latest such allegations made headlines last week when activists said they found the fresh graves of three soldiers from a special-forces brigade of the Russian military's Main Intelligence Directorate (GRU) that is based in Tambov, a city 400 kilometers south of Moscow. They suggested the men might have been killed in Ukraine.
Their claims came shortly after Ukrainian authorities detained two men they say are GRU soldiers wounded in a firefight while on a scouting mission in eastern Ukraine, where fighting between government forces and pro-Russian rebels has killed more than 6,100 people since April 2014.
The activists' findings sparked new waves of debate about the Russian military's alleged ongoing "large-scale reconnaissance operations" in eastern Ukraine despite a tenuous cease-fire.
Russia has denied it has sent troops into Ukraine, claiming that any Russian citizens fighting alongside separatists have gone there voluntarily and independently.
Moscow says the two men detained by Ukrainian armed forces quit the army in December, while the two said in a video distributed by Ukrainian officials that they are active GRU officers.
The new presidential decree makes activists' efforts to track down information about Russian military activities in Ukraine or elsewhere illegal if such military activities are officially defined as "special operations."
A report begun by Russian opposition politician Boris Nemtsov before his slaying in Moscow in late February and released by his political allies in mid-May alleged that more than 200 Russian troops had died so far in the fighting in eastern Ukraine.