The governor of Russia's Voronezh region said on Saturday that the army was taking "necessary military measures" in the region as part of a counter-terrorist operation declared after an armed mutiny by the Wagner mercenary group.
Earlier on Saturday, a Russian security source told Reuters that Wagner fighters had taken control of military facilities in the city of Voronezh, about 500 km (310 miles) south of Moscow. Reuters could not independently confirm that assertion.