Prigozhin has been at loggerheads with Russia's official political and military leadership for months, often criticizing not just the strategy in Ukraine but also the enrichment of Russia's elite at a cost of many lives on both sides.

 As of Friday evening, EST, Russian Joint Forces Deputy Commander General Sergey Surovikin demanded Wagner Group to stop their "rebellion" against Moscow, and detain their leader.

 Reports also suggest Russian forces have surrounded a Wagner Group headquarters, and that other elements of the mercenary army have breached the Russian borders from Ukrainian territory.

 This story is developing.