Russian President Vladimir Putin has said his country is fighting "the toughest battle for its future" as Wagner mercenary group chief Yevgeny Prigozhin leads an armed rebellion.
The 70-year-old addressed the nation on Saturday morning after mercenary chief Yevgeny Prigozhin and his troops reached a key Russian city.
A grave-looking Putin warned: "Everything has to be done in order to put this danger to rest. It is an attempt to subvert us from inside.
"This is treason in the face of those who are fighting on the front. This is a stab in the back of our troops and the people of Russia.
"We will not let this be repeated. We will defend our motherland including overcoming a number of obstacles."
He said the mutiny amounted to "a deadly threat to our statehood", and vowed "tough actions" in response.
"All those who prepared the rebellion will suffer inevitable punishment. The armed forces and other government agencies have received the necessary orders," Mr Putin said.
He called Mr Prigozhin's actions, without referring to the owner of the Wagner private military company by name, "a betrayal" and "a treason".
Mr Putin urged "those who are being dragged into this crime not to make a fatal and tragic, unique mistake, to make the only right choice - to stop participating in criminal acts".
Mr Prigozhin, the owner of the Wagner private military company, claimed that his forces now control military facilities in Rostov-on-Don.
"We will destroy anyone who stands in our way," Mr Prigozhin said in one of a series of video and audio recordings posted on social media, beginning late on Friday.
"We are moving forward and will go until the end," he added.
Mr Putin condemned the rebellion at a time when Russia was "fighting the toughest battle for its future" with its war in Ukraine.
"The entire military, economic and information machine of the West is waged against us," the Russian leader said.
"This battle, when the fate of our people is being decided, requires the unification of all forces, unity, consolidation and responsibility."
An armed rebellion at a time like this is "a blow to Russia, to its people", Mr Putin added.
"Those who plotted and organised an armed rebellion, who raised arms against his comrades-in-arms, betrayed Russia. And they will answer for it," the Russian President said.
Russia's security services responded to Mr Prigozhin's declaration of an armed rebellion by calling for his arrest.
In a sign of how seriously the Kremlin is taking the threat, security was heightened in Moscow, Rostov-on-Don and other regions.
It is not immediately clear how Mr Prigozhin was able to enter the southern Russian city or how many troops he had with him.
Shortly after Putin's address, the Ministry of Defence (MoD) said that "over the coming hours, the loyalty of Russia's security forces... will be key to how the crisis plays out" as Wagner forces appear to be moving towards the Russian capital.
The department tweeted that the feud between the Wagner group and the Russian defence ministry "escalated into outright military confrontation" in the early hours of Saturday.
"In an operation characterised by Prigozhin as a 'march for freedom', Wagner Group forces crossed from occupied Ukraine into Russia in at least two locations," the MoD said.
"In Rostov-on-Don, Wagner has almost certainly occupied key security sites, including the HQ which runs Russia's military operations in Ukraine.
"Further Wagner units are moving north through Vorenezh Oblast, almost certainly aiming to get to Moscow. With very limited evidence of fighting between Wagner and Russian security forces, some have likely remained passive, acquiescing to Wagner.
"Over the coming hours, the loyalty of Russia's security forces, and especially the Russian National Guard, will be key to how the crisis plays out.
"This represents the most significant challenge to the Russian state in recent times."
