LONDON — Vladimir Putin is facing a major military crisis after Russian mercenary leader Yevgeny Prigozhin declared war on Moscow’s own defense ministry, claiming Kremlin officials had killed thousands of his soldiers. 

The feud between Prigozhin and Russia’s ministry of defense has been building for months but now appears to have boiled over.

In response to Prigozhin’s allegations, Moscow issued a strong denial and announced that Russia’s FSB security service would open a criminal case against him. 

Prigozhin’s Wagner paramilitary group has been fighting alongside regular Russian soldiers and has been involved in some of the war on Ukraine’s bloodiest and most brutal clashes. 

For months, Prigozhin has blamed Moscow’s military leadership for incompetence and undermining his troops’ efforts. In his latest statements he called the Russian defense leadership “evil” and vowed to march for “justice,” threatening anyone who stood in his way. 

While Prigozhin insisted his statements did not represent a threat to Putin, the FSB said he was calling for an armed mutiny, the Russian state-owned TASS news agency reported Friday.

In a statement on his Telegram channel, Prigozhin blamed the Russian military — without offering evidence — for an attack on a Wagner camp that he said claimed the lives of thousands of his fighters.