Members of Wagner group in the city of Rostov-on-Don.
After Russian President Vladimir Putin denounced their military rebellion as "treason" in a crisis the Wagner leader Yevgeny Prigozhin has said his forces won't surrender.
On the one hand, Putin warned to put an end to what he described as an armed mutiny. CNN reports that Yevgeny Prigozhin, on the other hand, has asserted control over a number of military facilities and has sent some of his forces in the direction of Moscow.
The Wagner mercenary group's mutiny in Russia presented President Vladimir Putin with the most significant challenge to his long-standing leadership, drawing the attention of foreign leaders who were already keenly monitoring developments in this region owing to the Ukraine-Russia war.
Here are the reactions of nations and experts about the extraordinary situation due to which Vladimir Putin is facing the greatest threat to his authority in two decades:
"All parties to be responsible and to protect civilians. We're keeping a close eye on the situation and how it's evolving on the ground as we speak," British Prime Minister Rishi Sunak said.
"We're in touch with our allies as the situation evolves. I'll be speaking to some of them later today and the most important thing is for all parties to behave responsibly," he told the BBC.
Ukrainian President Volodymyr Zelensky said that the Wagner mutiny showed Russia was weak.
"Russia's weakness is obvious. Full-scale weakness. And the longer Russia keeps its troops and mercenaries on our land, the more chaos, pain, and problems it will have for itself later," he said in a statement on social media.
US President Joe Biden was briefed on the situation in Russia and Washington and "will be consulting with allies and partners on these developments", National Security Council spokesman Adam Hodge said.
European Union chief Charles Michel tweeted that the bloc was "closely monitoring the situation in Russia as it unfolds. In touch with European leaders and G7 partners."
"This is clearly an internal Russian issue," he wrote, adding that "our support for Ukraine" remains "unwavering".
NATO spokesperson Oana Lungescu said only the alliance was "monitoring the situation".