Russia’s most senior generals have dropped out of public view following a failed mercenary mutiny aimed at toppling the top brass, amid a drive by President Vladimir Putin to reassert his authority.

Unconfirmed reports say at least one person has been arrested, Reuters reported.

Armed forces chief of staff General Valery Gerasimov has not appeared in public or on state TV since the aborted mutiny on Saturday when mercenary leader Yevgeny Prigozhin demanded Gerasimov be handed over. Nor has he been mentioned in a defense ministry press release since June 9.

Gerasimov, 67, is the commander of Russia’s war in Ukraine, and the holder of one of Russia’s three “nuclear briefcases,” according to some Western military analysts.

Absent from view too is General Sergei Surovikin, nicknamed “General Armageddon” by the Russian press for his aggressive tactics in the Syrian conflict, who is deputy commander of Russian forces in Ukraine.

A New York Times report, based on a U.S. intelligence briefing, said on Tuesday he had advance knowledge of the mutiny and that Russian authorities were checking if he was complicit.

The Kremlin on Wednesday played down the report, saying that there would be a lot of speculation and gossip.

U.S. officials told Reuters on Wednesday that Surovikin had been in support of Prigozhin, but that Western intelligence did not know with certainty if he had helped the rebellion in any way.

The Russian-language version of the Moscow Times and one military blogger reported Surovikin’s arrest, while some other military correspondents who command large followings in Russia said he and other senior officers were being questioned by the FSB security service to verify their loyalty.

Reuters could not determine whether Surovikin had been arrested or was being screened, along with others, for their reliability in a more standard exercise.

Rybar, an influential channel on the Telegram messaging application run by a former Russian defense ministry press officer, said a purge was underway.

He said the authorities were trying to weed out military personnel deemed to have shown “a lack of decisiveness” in putting down the mutiny amid some reports that parts of the armed forces appear to have done little to stop Wagner fighters in the initial stage of the rebellion.

“The armed insurgency by the Wagner private military company has become a pretext for a massive purge in the ranks of the Russian Armed Forces,” Rybar said.

Such a move, if confirmed, could alter the way Russia wages its war in Ukraine — which it calls a “special military operation” — and cause turmoil in the ranks at a time when Moscow is trying to thwart a Ukrainian counteroffensive.

It could also cement or elevate the positions of other senior military and security figures regarded as loyal.

There was no official comment on what was going on from the defense ministry.

Some Russian and Western military and political analysts believe Defence Minister Sergei Shoigu, a veteran Putin ally who Prigozhin wanted to bring down with Gerasimov because of his alleged incompetence, may actually now be safer in his job.

“I think he (Prigozhin) actually expected something would be done about Shoigu and Gerasimov, that Putin would rule in his favor,” Michael Kofman, a Russian military specialist at the Carnegie Endowment think tank, wrote on Twitter.

“Instead, his mutiny may have ensured their continued tenure, despite being universally recognised as incompetent, and widely detested in the Russian Federation’s armed forces.”

General Viktor Zolotov, head of the National Guard and once Putin’s bodyguard, appears to be another beneficiary after appearing in public to say his men were ready to “stand to the death” to defend Moscow from Wagner.

He has spoken of the possibility of getting heavy weaponry and tanks for his forces in the wake of the mutiny.

Gerasimov was conspicuous by his absence when Putin on Tuesday thanked the army for averting a civil war, unlike Shoigu who has made several public appearances since.

Surovikin, Gerasimov’s deputy, was last seen on Saturday when he appeared in a video appealing to Prigozhin to halt his mutiny. He looked exhausted and it was unclear if he was speaking under duress.

Dara Massicot, an expert in the Russian military at the RAND Corporation think tank, said that something looked odd about the video, in which Surovikin has an automatic weapon on his lap.

“I noted a few days ago, there was something very off here. He’s not wearing his insignia or rank tabs. 30+ years in the military and he’s not got them on, even at night? Nope,” she wrote on Twitter.

There were unconfirmed Russian media and blogger reports on Wednesday evening that Surovikin was being held in Moscow’s Lefortovo detention facility after being arrested.

Alexei Venediktov, a well-connected journalist, said – without citing his sources – that Surovikin had not been in touch with his family since Saturday and that his bodyguards had gone silent too.

Lawrence Freedman, Emeritus Professor of War Studies at King’s College London, said Surovikin’s removal, if true, could be more destabilizing to Russia’s war effort than Saturday’s mutiny “especially if other associates of Prigozhin/Surovikin start to get purged.”

“Surovikin (is) a brute but also one of the more capable Russian commanders,” Freedman said on Twitter.