Wagner head Yevgeny Prigozhin has said in a Telegram post that all military sites in Rostov-on-Don are under the mercenary organisation's control.
Prigozhin says in the video message that he and his men are in the city's Southern District Military Headquarters.
Rostov governor Vasily Golubev wrote on Telegram that mass events planned in Rostov-on-Don for the weekend have been cancelled.
The Telegram channel of Yevgeny Prigozhin's press service posted a voice message on June 23, in which Prigozhin stated that the forces of the Ministry of Defense "hit our rear camps." The Russian Defense Ministry denied this information.
"There are 25,000 of us and we are going to figure out why chaos is happening in the country," he said.
Later, the National Anti-Terrorism Committee of the Russian Federation reported that after Prigozhin's statements, a criminal case was initiated on incitement to an armed rebellion.