Russian President Vladimir Putin accused Yevgeny Prigozhin, the commander of the Wagner mercenary group, of armed rebellion.
Russian media say that the focus of the crisis is Rostov.
The Wagner family is in Rostov-on-Don and is believed to be moving towards Voronezh and Moscow.
Russian sources report that Putin is at his workplace in the Kremlin, that he has not left Moscow.
Prigozhin refused to surrender.
EU and US leaders have announced that they are monitoring the situation and that Prigozhin is Russia's internal problem. There is speculation that there could be a battle for Moscow, while Ukrainian officials expect an outcome in the next 48 hours.
"The situation is difficult," Moscow Mayor Sobyanin said in a statement posted on Telegram.
He added that it is possible that some roads or neighborhoods in the city will be closed to traffic.
Sobyanin said that an anti-terrorist operation regime has been declared in Moscow, which means restricting the movement of people and traffic, and monitoring and restricting communications, as well as that Monday will not be a working day, in order to "minimize the risks". He urged Muscovites to "refrain from traveling around the city as much as possible." "City services are on the highest alert," he wrote in a statement on Telegram.
In a video posted this morning on a Telegram channel associated with the Wagner Group, its leader Yevgeny Prigozhin is seen meeting with Russian Deputy Defense Minister Yunus-Bek Yevkurov.
With the help of biometric facial comparison technology, the BBC confirmed with, as it is stated, a high degree of reliability, the identity of Yevkurov.
Russian diplomacy claims that the rebellion will not prevent Moscow from "achieving its goals" in Ukraine.
S.Ć./Danas
Read daily news, analysis, commentary and interviews at www.vreme.com
