President Vladimir Putin on Thursday declared all deaths of Russian soldiers during special operations to be classified as a state secret, a move that comes as Moscow stands accused of sending soldiers to fight in eastern Ukraine.
Putin, who has repeatedly denied any involvement of Russian troops in a pro-Russian rebellion there, amended a decree that had previously classified only deaths of servicemen during war time as secret.
Asked to explain the rationale behind Putin's move, his spokesman Dmitry Peskov had no immediate comment.
Russian opposition activists released a report saying at least 220 serving Russian soldiers were killed in fighting in two hot spots in east Ukraine last summer and earlier this year.
Russia annexed Crimea from Ukraine in March, 2014, after wresting control over the peninsula by deploying troops with no insignia. Russia initially vehemently denied the soldiers - who became to be known as "little green men" - were Russian troops.
Putin only publicly admitted Russian soldiers had been deployed in Crimea nearly a month after signing legislation formally completing the peninsula's annexation.
Troops on border
Unrest soon moved to east Ukraine. The West now accuses Moscow of driving a separatist rebellion there by providing it with serving Russian troops, arms, training and intelligence.
Russia has backed many of the separatists' political claims, but it denies direct military involvement in east Ukraine, where more than 6,100 people have been killed in more than a year of fighting between the rebels and Kiev's forces.
A Reuters reporter witnessed earlier this week the Russian army massing troops without insignia and hundreds of pieces of unmarked weaponry on the border with Ukraine.
Asked by Reuters if this indicated Russia planned an invasion of Ukraine, Kremlin spokesman Peskov told a conference call with reporters: "I find the wording of this question, 'if an invasion is being prepared', inappropriate as such."
A cease-fire has been in force in eastern Ukraine since February, but each side accuses the other of violations. Kyiv says it fears Russia could commit troops to a push to extend control by separatist forces along Ukraine's southern coast.