British officials said Saturday they are monitoring the situation in Russia. "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," Britain's Defense Ministry said in a tweet.
Prigozhin said Friday that Wagner field camps were struck by rockets, helicopter gunships and artillery fire on orders from the chief of the military's General Staff, General Valery Gerasimov. He charged that Gerasimov issued the order after a meeting with Defense Minister Sergei Shoigu, at which they decided to destroy Wagner.
The Russian Defense Ministry rejected Prigozhin's claims.
Prigozhin said the Wagner Group commanders' council has vowed to punish Shoigu.
"The evil that the military leadership of the country is responsible for must be stopped. They neglect the lives of soldiers, they forgot the word 'justice,' which we will bring back," he said.
"Therefore, those who killed our guys today, those who killed tens, many tens of thousands of lives of Russian soldiers, will be punished," he said, announcing that his forces would march to secure justice for the lost fighters.
Russia's Federal Security Service, the FSB, opened a criminal investigation on Friday against Prigozhin, accusing him of armed mutiny, citing the National Anti-Terrorism Committee, an arm of the FSB.
The crime is punishable by up to 20 years in prison, according to Russia's chief prosecutor.
Political analyst Tatiana Stanovaya told The Associated Press this may well be the last of Prigozhin.
"Now that the state has actively engaged, there's no turning back," she posted on Twitter. "The termination of Prigozhin and Wagner is imminent. The only possibility now is absolute obliteration, with the degree of resistance from the Wagner group being the only variable. ... Confrontation seems totally futile."
Prigozhin Friday said the Kremlin's reasoning for invading Ukraine is based on lies fabricated by the army's top brass. He has for months openly accused Shoigu and Gerasimov of gross incompetence.
"The Defense Ministry is trying to deceive society and the president and tell us a story about how there was crazy aggression from Ukraine and that they were planning to attack us with the whole of NATO," Prigozhin said in a video clip released on Telegram by his press service.
He went on to accuse Shoigu: "The war was needed ... so that Shoigu could become a marshal ... so that he could get a second 'Hero' [of Russia] medal," he added. "The war wasn't needed to demilitarize or denazify Ukraine."
The Wagner chief also attacked the ruling elite, saying greed fueled its desire to absorb the assets from Ukraine's Donbas region. "The task was to divide material assets," he said. "There was massive theft in the Donbas, but they wanted more."