Updated

Yevgeny Prigozhin, the founder of Russia's Wagner Group who challenged the rule of Vladimir Putin just months ago, was killed Wednesday in a plane crash that has left 10 people dead outside of Moscow, state media is reporting.

The business jet was traveling from the Russian capital to St. Petersburg when it went down in the Tver region, according to the TASS news agency.

"Prigozhin was listed among the passengers, according to the Federal Air Transport Agency," read a post by TASS on Telegram. "An investigation into the crash of the Embraer aircraft has been launched, the department noted."

It was not immediately clear whether Prigozhin is among the 10 reported to have died in the crash, but Russian state media later said he had died. The Pentagon told Fox News Digital that it is monitoring the situation.

WHO IS YEVGENY PRIGOZHIN?

Plane crash in Russia reportedly involving Yevgeny Progozhin

A view shows plane wreckage on fire following an alleged air accident at a location given as Tver region, Russia, on Wednesday. (Reuters/Ostorozhno Novosti)

"We have seen the reports. If confirmed, no one should be surprised," White House National Security Council spokesperson Adrienne Watson said in a statement. "The disastrous war in Ukraine led to a private army marching on Moscow, and now — it would seem — to this."

Earlier, President Biden was asked about reports that Prigozhin was possibly on the doomed aircraft. 

"I don't know for a fact what happened, but I am not surprised...Not much happens in Russia that Putin's not behind. I don't know enough to know the answer," he said.

Rebekah Koffler, a strategic military intelligence analyst and former senior official at the U.S. Defense Intelligence Agency (DIA), told Fox News Digital that reports by Russian state media should be looked at with skepticism, given Moscow's agenda. 

Businessman Yevgeny Prigozhin shows Russian Prime Minister Vladimir Putin

Businessman Yevgeny Prigozhin, right, shows Russian President Vladimir Putin his school lunch factory outside Saint Petersburg. The European Union in October 2020 sanctioned Prigozhin — nicknamed "Putin's chef" because his company Concord has catered for the Kremlin — accusing him of undermining peace in Libya by supporting the Wagner Group private military company. (ALEXEY DRUZHININ/SPUTNIK/AFP via Getty Images)

"At this time, we lack independent confirmation whether the Russian media or the Federal Air Transport Agency reporting about Prigozhin’s death is credible," she said. "There could be many reasons why Moscow wants us to believe that Prigozhin is dead. If he indeed died in the plane crash, it’s probably a result of the assassination operation, ‘wet deeds’ in Russian tradecraft, conducted on Putin’s orders." 

"If Prigozhin is alive, the story could be a disinformation operation, intended to get Prigozhin back under cover to run clandestine operations in Africa and other places vital for Putin," Koffler added. "What I don’t rule out is either way, it’s not a coincidence that it happened today, on the day of the GOP presidential debates. The story that originated in the Russian media has hijacked the U.S. news cycle. Prigozhin has become the ninth personality, along with the actual presidential candidates that the media is covering."

One of Wagner's Telegram channels also confirmed Prigozhin's death, calling it "a big tragedy for the Fatherland" but adding that it was "God's will."

"That our best warriors perished is God’s will. Everyone of us is ready for this. The one who orchestrated this thinks that he has won, but it is not so. If this is done by an external enemy - which is unlikely - it only precipitates and exacerbates his inevitable defeat. If this is a knife in the back . . . the Fatherland will survive this," it said. 

Russia jet crash

This image released by Ostorozhno Novosti on Wednesday shows the crash site of a private jet near the village of Kuzhenkino, Tver Region, Russia. (AP)

"Bigger things have happened and will happen . . . but your fate, as the fate of any 'Judah' is not enviable and while the history is being written, the tale of this heinous betrayal will be the scarlet letter on your kin," the social media post continued. "Whatever the fate of the Wagner Group is, one cannot take away our victories. Yevgenij Viktorovich Prigozhin, the greatest commander in modern history, has given his life in the fight against the enemies of the Fatherland. And memory about our heroes is immortal."

Putin, meanwhile, made a public appearance at a concert in Russia after the news of the crash emerged. His press secretary, Dmitry Peskov, told Russian news media that Putin "has been informed of all the events around Prigozhin" and that "necessary measures are being taken."

Prigozhin plane crash

The crash site of a private jet near the village of Kuzhenkino, Tver Region, Russia. (AP)

In late June, Prigozhin initiated what observers called the most significant challenge to Putin’s regime in his 23 years in power. 

After marching his 25,000-strong mercenary forces to within 125 miles of Moscow, Prigozhin abruptly ended the operation and ordered his troops to return home before heading into exile in Belarus. 

Yevgeny Prigozhin speaks

In this image taken from video released by the Razgruzka_Vagnera telegram channel on Monday, Yevgeny Prigozhin, the owner of the Wagner Group military company, speaks to a camera at an unknown location.  (Razgruzka Vagnera Telegram channel via AP)

The reported crash comes just days after Prigozhin posted a new video on Telegram proclaiming that the Russian mercenary force Wagner Group would make Russia "greater" and Africa "freer."

The video was posted Monday from, what Prigozhin claimed, was somewhere in Africa.

In the video, Prigozhin said the Wagner Group is conducting reconnaissance and search activities and "making Russia even greater on all continents, and Africa even freer."

Russia plane crash outside of Moscow

A view shows a plane falling following an alleged air accident reportedly involving Wagner Group founder Yevgeny Prigozhin on Wednesday. (Reuters/Ostorozhno Novosti)

"Justice and happiness for African nations. Giving hell to ISIS, Al Qaeda, and other bandits," Prigozhin said, noting temperatures there were topping 120 degrees Fahrenheit.

"Recruiting real warriors and continuing to complete the tasks that have been given and we had promised to master," Prigozhin also said while toting an assault rifle and wearing military fatigues. Pickup trucks and other people dressed in fatigues were seen in the background.

PRIGOZHIN APPEARS PUBLICLY FOR FIRST TIME SINCE MUTINY

Yevgeny Prigozhin, the owner of the Wagner Group military company

Yevgeny Prigozhin is pictured in Rostov-on-Don, Russia, on June 24, 2023. (AP Photo, File)

The Central African Republic is one of the countries where Wagner's soldiers-for-hire have been active and accused of committing human rights abuses.

The Kremlin has used the Wagner Group since 2014 as a tool to expand Russia's presence in the Middle East and Africa.

Prigozhin spent months criticizing Russia's military performance in Ukraine before he called for an armed uprising on June 23 to oust the defense minister and headed from Ukraine toward Moscow with his mercenaries.

Under a deal brokered by Belarusian President Alexander Lukashenko, Prigozhin agreed to end his rebellion in exchange for amnesty for him and his fighters and permission to relocate to Belarus.

Putin at concert in Russia

Russian President Vladimir Putin, whose rule recently was challenged by Yevgeny Prigozhin, appears Wednesday at a concert in Russia after news emerged of the crash allegedly involving the Wagner Group founder. (Fox News)

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Putin branded Prigozhin a traitor as the revolt unfolded and vowed harsh punishment, but the criminal case against the mercenary chief on rebellion charges was later dropped. The Kremlin said Putin had a three-hour meeting with Prigozhin and Wagner Group commanders days after the rebellion.

Fox News Digital's Thomas Ferraro, Bradford Betz and Peter Aitken and The Associated Press contributed to this report.