Members of Wagner group sit atop of a tank in a street in the city of Rostov-on-Don, on 24 June 2023. President Vladimir Putin said an armed mutiny by Wagner mercenaries was a "stab in the back" and that the group's chief Yevgeny Prigozhin had betrayed Russia, as he vowed to punish the dissidents. Photo: STRINGER / AFP
From BBC news updates*
Rebel Wagner forces appear to be halfway to Moscow from the city of Rostov, which they claim to control, creating a "significant challenge" to the Russian state, the UK's Ministry of Defence says.
Earlier, Russian President Vladimir Putin spoke publicly for the first time since Yevgeny Prigozhin, the head of the Wagner mercenary group, vowed to "go all the way" to topple Russia's military leadership.
In an emergency televised address, Putin said that the "armed mutiny" by the Wagner Group forces is treason.
BBC News Russian sources say Wagner fighters have taken control of all military facilities in the city of Voronezh, a halfway point between Rostov-on-Don - the first city Wagner said it had taken - and Russia's capital Moscow.
Voronezh city officials were yet to publicly comment on the claim, however Voronezh region governor Aleksandr Gusev warned there were many fake reports circulating about an armoured column in the region.
He said the Russian armed forces were now carrying out "operational and combat measures" in the Voronezh region as part of the early declared counter-terrorist operation.
A Reuters journalist saw army helicopters open fire at an armed Wagner column that was advancing past the city of Voronezh with troop carriers and at least one tank on a flatbed truck.
This video grab taken from handout footage posted on June 24, 2023 on Telegram shows Yevgeny Prigozhin speaking inside the headquarters of the Russian southern military district in the city of Rostov-on-Don. Photo: HANDOUT / AFP
An intelligence update from the UK said some Wagner units "are moving north through Vorenezh Oblast, almost certainly aiming to get to Moscow".
It confirmed Wagner had "almost certainly" occupied key sites in Rostov-on-Don, and described the rebellion as "the most significant challenge to the Russian state in recent times", which was escalating into an "outright military confrontation".
Wagner Group forces had "crossed from occupied Ukraine into Russia in at least two locations", the update said.
And some Russian troops "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," it said.
Both Prigozhin and the Russian defence ministry were actively urging armed men on the opposing side to switch allegiance.
The governor of the Lipetsk region - located between the city of Voronezh and the capital Moscow - has asked residents to avoid leaving their homes and to refrain from travelling, either with private vehicles or on public transport.
"The situation is under control, but requires understanding on the part of every inhabitant of the region," he said a statement.
Zelensky, others in region react
Ukraine President Volodymyr Zelensky, posting on social media, says anyone who "chooses the path of evil destroys itself", and that "Russia's weakness is obvious".
Although he does not mention Russia's President Putin by name, Zelensky appears to criticise the Russian leader for "throwing hundreds of thousands" into war.
Ukrainian army medics, bringing wounded soldiers from the nearby frontlines around Bakhmut in eastern Ukraine, welcomed news of the military rebellion in Russia.
"If there's a revolution in Russia, I'm going to get drunk!" grinned one, in the small town of Chasiv Yar.
But others were wary about predicting what impact it might have on the war.
"I hope it helps us," said another experienced military doctor. "But I'm not sure I believe it. It seems more like some kind of show, rather than a real revolution."
With Ukraine in the middle of a key counter offensive, there's a possibility that the country will rush to take advantage of the chaos - and the likely drop in Russian troop morale.
The governor of the Rostov region, Vasiliy Golubev, took to Telegram to urge people to stand with Putin: "There have been times in the history of Russia when some wanted to separate our society and stoke the flames of civil war... it led to a catastrophe."
He added: "This cannot be allowed to happen again. The Rostov region sides with the President! Dear fellow countrymen, we must be united!"
Putin speaks
In a video statement, Putin said some Russians have been "tricked into a criminal adventure" - without specifically mentioning rebellious Wagner fighters.
Putin said Russia's future is at stake, describing the actions of mutineers as a "stab in the back".
This screen grab taken from a footage released by the Russian presidential press office on 24 June 2023 shows Russian President Vladimir Putin making a statement in Moscow. Photo: HANDOUT / AFP
The high "ambitions" of some have led to "high treason", he said.
The Russian president also warned of "inevitable punishment" for those dividing the Russian society.
He said a counter-terrorism regime is now in place in the capital Moscow and several other regions.
Earlier the Kremlin accused Prigozhin of "armed rebellion".
Prigozhin said his Wagner fighters had crossed the border from Ukraine into Russia, entering the city of Rostov, and his men would destroy anyone who stood in their way.
From there, he said he would move on to Moscow, a distance of about 1000km.
In a message posted to Telegram on Saturday morning, Prigozhin said that all the members of his Wagner group of mercenaries were "ready to die" in his action against the Russian military.
"All of us are ready to die. All 25,000, and then another 25,000," he said in an audio message, adding the action was being taken "for the Russian people".
Video has been posted this evening claiming to show Prigozhin inside Russia's southern military headquarters in Rostov-on-Don.
In one video Prigozhin said his troops would blockade the city and move on to Moscow unless Defence Minister Sergei Shoigu and General Valery Gerasimov come to meet them.
"We have arrived here, we want to receive the chief of the general staff and Shoigu. Unless they come, we'll be here, we'll blockade the city of Rostov-on-Don and head for Moscow," he says.
The local governor urged citizens there to keep calm and stay indoors.
A resident of Rostov-on-Don told BBC News Russian that the entire city centre was surrounded and blocked off.
There were soldiers around, said the person, who asked not to be named: "When [we] asked who they are, the soldiers said 'we're just good people'."
"The situation in the city is calm: there is no panic, everything is like on a normal day."
They also said that streets a ten-minute walk from the military headquarters, which Wagner claimed to have seized, "seem to be free" but the area near the military building was "tightly surrounded".
Prigozhin claimed that his forces had shot down a Russian military helicopter that "opened fire on a civilian convoy". He did not give a location and the assertion could not be immediately verified.
Who is the Wagner group?
The Wagner Group is a private army of mercenaries that has been fighting alongside the regular Russian army in Ukraine.
Members of Wagner group sit atop of a tank in a street in the city of Rostov-on-Don, on 24 June 2023. Photo: STRINGER / AFP
It was first identified in 2014, and the UK's Ministry of Defence says Wagner started recruiting in large numbers in 2022 because Russia had trouble finding people for its regular army.
About 80 percent of Wagner's troops in Ukraine have been drawn from prisons, the US National Security Council said at the start of this year.
Tension has been growing between them over how the war has been fought, with Prigozhin launching vocal criticisms of Russia's military leadership in recent months.
On Friday local time, the 62-year-old mercenary leader accused the military of launching a deadly missile strike on his troops and vowed to punish them. He did not provide evidence.
Authorities have denied the strike and demanded he halt his "illegal actions".
Prigozhin said the "evil" in Russia's military leadership must be stopped and vowed to "march for justice".
"Those who killed our lads, and tens of thousands of lives of Russian soldiers [in the war in Ukraine] will be punished," he said in an audio message posted to the social media platform Telegram.
"I ask you not to resist. Anyone who does will be considered a threat and destroyed. That goes for any checkpoints and aviation on our way.
"Presidential power, the government, the police and Russian guard will work as usual.
"This is not a military coup, but a march of justice. Our actions do not interfere with the troops in any way."
Prigozhin's declared move against the Russian military leadership is "almost certainly an attempted coup", the former US Ambassador to Ukraine Bill Taylor has told the BBC.
"This is serious for Putin. The Russians are taking this very seriously, and it sounds like they should."
But Taylor, who was in Ukraine last month, said the Wagner boss is unlikely to succeed.
"The ministry of defence forces have the equipment, have the aircraft, have the tanks - they have the military equipment in numbers - to put down Prigozhin's forces," he said.
But the Russian infighting could potentially help Ukraine in its fight to defeat Russia's invasion, Taylor said.
"If the Russians are now worried about their chain of command, then the Russians that are supposed to be fighting the Ukrainians may be distracted and may even run."
Yevgeny Prigozhin, head of the Wagner group, speaking in Bakhmut in a video released on 3 March 2023. Photo: AFP / Telegram channel @concordgroup_official
Security tight in Moscow, other nations watching closely
Security in Moscow was stepped up on Friday night at prime locations in Moscow, including government buildings and transport facilities, Russia's state-owned news agency TASS said.
The governor of Russia's Lipetsk region is also asking residents not to travel south.
Lipetsk is around 280km north-east of the nearest Ukrainian border, and more than 500km north of Rostov.
Writing on Telegram, Igor Artamonov said security measures in the region are being tightened, with a particular focus on protecting critical infrastructure facilities.
In a tweet late on Friday, the Ukrainian Ministry of Defence said simply: "We are watching."
The White House said it was monitoring the situation and would consult with US allies.
Gen Sergei Surovikin, the deputy head of the Russian forces in Ukraine, whose leadership Prigozhin has praised in the past, called on him to "stop the convoys and return them to their bases".
"We are of one blood, we are warriors," he said in a video. "You mustn't play into the enemy's hands at a time that is difficult for our country."
Another senior commander, Lt Gen Vladimir Alekseyev, described the Wagner chief's actions as "a stab in the back of the country and the president".
In this file photo taken on September 20, 2010 Businessman Yevgeny Prigozhin shows Russian Prime Minister Vladimir Putin his school lunch factory outside Saint Petersburg. Photo: AFP
Russian state media reported that the FSB, Russia's security services, have opened a criminal case against Prigozhin, accusing him of "calling for an armed rebellion" and attempting to start armed civil conflict in Russia.
The FSB also reportedly called on Wagner fighters to disobey Prigozhin's orders and to take steps to apprehend him.
Russia's defence ministry said in a statement that "all reports by Prigozhin spread on social media" of Russian strikes on Wagner camps were "not true and are an information provocation".
It comes after a video message in May in which Prigozhin stood surrounded by the bodies of his troops and berated Russian defence minister Sergei Shoigu - as well as Chief of the General Staff Valery Gerasimov - for not providing them with enough ammunition.
On Friday, he declared that the war in Ukraine had been started "so that Shoigu could become a Marshal".
"The Ministry of Defence is trying to deceive the public, deceive the president and tell a story that there was some crazy aggression by Ukraine, that - together with the whole Nato bloc - Ukraine was planning to attack us," he said.
* This story was first published by the BBC with updates from the BBC live blog.