A woman watches Russian President Vladimir Putin delivering a televised address to the nation in Moscow on Saturday. The speech came after Wagner Group chief Yevgeny Prigozhin said his troops had occupied the Russian military headquarters in Rostov-on-Don. Photo by Sergei Ilnitsky/EPA-EFE

“We will defend both our people and our statehood from any threats, including internal treachery. What we have been confronted with can be precisely called treachery,” Putin said, according to the official TASS news agency. “The unbounded ambitions and personal interests have led to a treason and a betrayal of the country and its people.”

Describing Prigozhin’s actions as “a betrayal” and “a knife in the back of our people,” the Russian leader vowed that a civil war “will not be allowed to repeat itself in the country.”

Putin’s 24-year grip on the country appeared to be hanging in the balance in the hours after Prigozhin accused the Russian military of launching a deadly strike on his troops and vowed to retaliate.

In his video released earlier on Friday, Prigozhin accused the Russian elite of pillaging Ukraine’s eastern Donbas region since 2014, asserting they wanted more of the country and then lied about the reasons for the war.

“The Ministry of Defense 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.

The Kremlin responded by ordering the Federal Security Service to open a criminal case into what it called Prigozhin’s “call for an armed mutiny” and urged Wagner fighters not to obey his orders and to put him under arrest.

Prigozhin on Saturday claimed his fighters had taken control of all military installations the southern Russian city of Rostov-on-Don after marching his men out of Ukraine and multiple reports indicated his troops are heading north toward the Russian capital.

In an audio message posted on Wagner’s Telegram page, Prigozhin said his forces took the HQ of Russia’s Southern Military District “without a single shot being fired [by us],” the BBC reported.

British military analysts said Wagner troops had taken key security security sites in Rostov-on-Don, including the southern headquarters, which runs all of Russia’s military operations in Ukraine, and were now moving north, encountering little miliary resistance.

Prigozhin is “almost certainly aiming to get to Moscow,” the British Ministry of Defense said in an intelligence update, calling the situation “the most significant challenge to the Russian state in recent times.”

Ukrainian President Vladimir Zelensky made his first comments on the situation Saturday, stating in a Twitter post that Russia has relied on propaganda to mask its weakness but now “there is so much chaos that no lie can hide it.”

The longer Russia continues its all-out war against Ukraine, the more problems it risks facing on its own territory, he wrote.

“Everyone who chooses the path of evil destroys himself. Who sends columns of troops to destroy the lives of another country and cannot stop them from fleeing and betraying when life resists,” he wrote.

U.S. Secretary of State Antony Blinken said Saturday he had spoken to the Group of Seven foreign ministers and the European Union’s foreign affairs chief about the situation in Russia.

The United States, he said, “will stay in close coordination with Allies and partners as the situation continues to develop.”

In an indication of how seriously Putin is taking the threat to his control of the country, on Saturday he signed a law establishing 30-day jail sentences for those violating martial law where it has been imposed, Russian news agency RIA Novosti reported.