Tanks have been deployed on the streets of Moscow amid fears of an imminent Wagner Group coup to overthrow Vladimir Putin.
The group's outspoken leader, Yevgeny Prigozhin has vowed revenge on the Kremlin after blaming Defense Minister Sergei Shoigu for a missile attack on its Bakhmut training camp in Ukraine, which killed more than 50 soldiers.
Hailing Wagner's efforts as a "march of justice" rather than a coup, however, Prigozhin declared on Friday: "We're on our way to Moscow, and anyone who entered our centres will answer for it."
Security services reacted to the threat immediately, meanwhile, by opening a criminal investigation into the 62-year old - calling for his arrest on charges of inciting an "armed rebellion" over threats to oust Shoigu.
Kremlin spokesman Dmitry Peskov added that "all the necessary measures were being taken" and confirmed that Putin has been informed about the escalating situation.
Footage from the Russian capital on Friday night showed armoured vehicles occupying the streets with military officials and roadblocks guarding both the Kremlin and the country's parliamentary State Duma building.
Elsewhere, further armoured vehicles and tanks were spotted in Rostov, which is seen as an important crossing point for Russia's military operation.
Indeed, Prigozhin acknowledged on Saturday morning that his forces had driven into the southern city, where they faced no resistance.
With young checkpoint troops reportedly standing back, Prigozhin said his forces "aren't fighting against children."
"But we will destroy anyone who stands in our way," he added. "We are moving forward and will go until the end."
In a later audio message, meanwhile, the Wagner leader claimed he was "ready to die" as he headed to Moscow alongside 25,000 fighters.
"All of us are ready to die. All 25,000, and then another 25,000," he said. "We are dying for the Russian people."
The man sometimes referred to as 'Putin's Chef' then claimed on Telegram that the group had downed a Russian military helicopter in the region, after it "opened fire on a civilian convoy".
As videos on social media appeared to show clashes between Russian forces and Wagner troops, a regional governor issued a plea to families in the area to stay indoors.
"The current situation requires the maximum concentration of all forces to maintain order," Vasily Golubev said, also on Telegram.
"Law enforcement agencies are doing everything necessary to ensure the safety of residents of the area.
"I ask everyone to stay calm and do not leave the house without the need."
Hours earlier in a video rant circulated on social media after television channels were reportedly hacked, Prigozhin said: "PMC Wagner Commanders’ Council made a decision, the evil brought by the military leadership of the country must be stopped. They neglect the lives of soldiers. They forgot the word "justice", and we will bring it back.
"Those, who destroyed today our guys, who destroyed tens, tens of thousands of lives of Russian soldiers will be punished.
"I’m asking: no one resist. Everyone who will try to resist, we will consider them a danger and destroy them immediately, including any checkpoints on our way. And any aviation that we see above our heads. I’m asking everyone to remain calm, do not succumb to provocations, and remain in their houses.
"Ideally, those along our way, do not go outside. After we finished what we started, we will return to the frontline to protect our motherland.
"Presidential authority, Government, Ministry of Internal Affairs, Rosgvardia, and other departments will continue operating as before.
"We will deal with those who destroy Russian soldiers. And we will return to the frontline. Justice in the Army will be restored. After this, justice for the whole of Russia."
