The Kremlin on Thursday denied a report by the independent Novaya Gazeta Europe that an undisclosed clause in President Vladimir Putin's decree on partial mobilisation provided for one million reservists to be enlisted to fight in Ukraine.
The state-owned news agency RIA cited Kremlin spokesman Dmitry Peskov as calling the report "a lie".
Novaya Gazeta Europe, a spin-off of the now-shuttered Russian investigative newspaper, cited an unnamed source in the presidential administration as saying that point 7 of the decree, which was withheld as "For official use" in Wednesday's public release, allowed the armed forces to draft a million personnel.
Defence Minister Sergei Shoigu said on Wednesday that around 300,000 reservists would be called up, and that they would be specialists with combat experience, although no figure appeared in the decree as published on official websites.
He said Russia had 25 million reservists at its disposal in all.
All Russian men are required to do a year's military service between the ages of 18 and 27, although university students may instead receive instruction from a military faculty alongside their chosen studies.