President Vladimir Putin has been briefed on the developments with Wagner and "necessary measures are being taken", Interfax news agency said, citing Kremlin spokesman Dmitry Peskov.
Russia's FSB security service has opened a criminal case against mercenary chief Yevgeny Prigozhin for calling for armed mutiny, the TASS news agency also said, citing the National Antiterrorism Committee.
Prigozhin on Friday accused the Russian military of "destroying" his fighters, without fully explaining his accusation, and vowed to stop the "evil" of the military leadership.
