General Sergei Surovikin, the deputy commander of the Russian group of forces fighting in Ukraine, is believed to have been detained days after mercenaries staged a revolt inside Russia,

Two people familiar with the matter spoke to The Associated Press, citing US and Ukrainian intelligence assessments.

It’s not clear whether General Surovikin – nicknamed “General Armageddon” by the Russian media – faces any charges or where he is being held, reflecting the opaque world of the Kremlin’s politics and uncertainty after the revolt.

But his reported detention comes days after Wagner Group mercenaries took over the military headquarters in the Russian city of Rostov-on-Don and were heading toward Moscow in what appears to have been an aborted insurrection.

Wagner head Yevgeny Prigozhin has spoken positively of General Surovikin while criticising the country’s military brass and suggested that he should be appointed the general staff chief to replace General Valery Gerasimov.

The New York Times this week reported that US officials believed General Surovikin had advance knowledge of Mr Prigozhin’s plan to stage the revolt.

The White House and the Kremlin declined to comment.

Earlier this week, Kremlin spokesman Dmitry Peskov referred questions about General Surovikin to the defence ministry, which has so far made no statement about him.

Asked if Mr Putin still trusted General Surovikin, Mr Peskov said: “He (Putin) is the supreme commander-in-chief and he works with the defence minister and with the chief of the General Staff.”

General Surovikin, who has long-time links to Mr Prigozhin, hasn’t been seen since the start of the rebellion, when he posted a video urging an end to it.

He had looked exhausted in that video and it was unclear if he was speaking under duress.

A Russian military blogger, the Moscow Times, and the Financial Times reported that General Surovikin, who is also the commander of the Russian air force, has been arrested.

There has been intense speculation that some top military officers may have colluded with Mr Prigozhin and may now face punishment for the mutiny that briefly sent a virtually unchallenged march toward Moscow that Mr Putin has labelled treason and a “stab in the back”.

Alexei Venediktov, former head of the Ekho Moskvy, a prominent independent radio station that was shut down by authorities after Moscow invaded Ukraine, said General Surovikin and his close lieutenants hadn’t been in contact with their families for three days, but stopped short of saying that he was detained.

Another prominent military messaging channel, Rybar, which is run by a former defence ministry press officer, reported a purge in the ranks was underway as authorities looked into allegations that some could have sided with Mr Prigozhin.

General Surovikin has been linked to Mr Prigozhin since when both were active in Syria, where Russia has waged a military action since 2015 to shore up Syrian President Bashar Assad’s government and to help him reclaim territory after a devastating civil war.

General Gerasimov’s own fate also is unclear after the abortive mutiny. While Defence Minister Sergei Shoigu has showed up at several events attended by Mr Putin, General Gerasimov was mysteriously absent.

If a purge is indeed underway, it could destabilise the military chain of command and erode troop morale amid the early stage of Ukraine’s latest counteroffensive and offer Kyiv a chance to reclaim more ground.

-with AAP