Putin's clashing warlords are on the verge of full-blown violence that could weaken his grip on power

• The ongoing feud between Putin's warlords came to the brink of violence on Friday.
• Wagner boss Yevgeny Prigozhin went on a tirade against the Defense Ministry, prompting calls for his arrest.

While much of the world is still wondering what exactly went wrong with the Titan submersible, Russian President Vladimir Putin may be wondering the same thing about the implosion currently happening among his warlords.

The escalating feud between Russia's Ministry of Defense and the Wagner Group leader Yevgeny Prigozhin turned into an all-out brawl late Friday and into Saturday that had some in Russia worried about the prospect of a coup that could start to destabilize Putin's authoritarian regime.

Prigozhin, the mercenary boss and former close ally of Putin's, posted a tirade on Telegram in which he said Russia's Defense Ministry "must be stopped," accused them of ordering deadly missile strikes on his forces, and called for retaliation. Russia denied his claims and the supposed strikes have not been independently verified.

Prigozhin called for Russians to join him and his cadre of seasoned fighters many thousands strong in the most shocking suggestion that he was leading an armed rebellion, later claiming he was entering Russia.

"The evil carried by the country's military leadership must be stopped," Prigozhin said, adding that his 25,0000 mercenaries were ready to stand against Russia's Defense Ministry. He also claimed Russia's justification for invading Ukraine was a "racket" and that the war was initiated to profit Russian elites.

The FSB, Russia's security service and successor to the Soviet-era KGB, quickly responded by opening a criminal case against Prigozhin for "calling for an armed rebellion." Russian generals pleaded with Wagner Group mercenaries to stop an apparent coup or show of force underway, warning it could ignite a civil war.

A Kremlin spokesperson told the media Putin was aware of Prigozhin's comments and that "necessary measures are being taken."

The FSB also called on Wagner mercenaries, who played a key role in Russia's efforts in Ukraine, to ignore orders given by Prigozhin and work to help arrest him, according to the news site Meduza.

The development has sparked alarm in Russia. Meanwhile, videos shared by Meduza showed armored military vehicles on the streets of Moscow Friday evening.

It's still unclear if the feud will translate into fighting among Russians, but it's the most intense infighting among Russian military forces to occur since the invasion of Ukraine in February of last year and comes as Ukrainian forces continue with their counteroffensive. It may also be the most instability experienced in Russia in all of Putin's rule.

The stakes of the fighting are high for Putin, whose reliance on warring warlords has previously come under scrutiny. Insider's Ryan Pickrell previously reported that Putin plays Prigozhin and the Defense Ministry against each other, escalating tensions between those factions and attempting to deflect blame off himself.

"Putin has been an effective user of divide-and-rule until now, but this seems like it's gotten to a point where not intervening somehow calls into question the ability of the center to control things to an uncomfortable degree," Simon Miles, an assistant professor at Duke University's Sanford School of Public Policy and a historian of the Soviet Union and US-Soviet relations, told Insider on Friday.

Tatiana Stanovaya, a senior fellow at the Carnegie Russia Eurasia Center, also said Friday that many Russian elite will blame Putin "for letting the situation escalate to such extremes and for his lack of a timely, adequate response when to many it was evident that Prigozhin was pushing the limits of Kremlin's tolerance."

"Therefore, this entire saga is also an undercut to Putin's standing," she said.

Prior to his tirades Friday, Prigozhin was bashing Russia's Defense Ministry for months, especially targeting Russian Defense Minister Sergey Shoigu and Chief of the Russian General Staff General Valery Gerasimov.

He has issued scathing statements criticizing the Defense Ministry's failures on the battlefield and lack of support for his Wagner forces, prompting many to wonder how he was getting away with the outward hostility in a country that was heavily censoring commentary around the war.

It appears his statements on Friday finally went too far.