Russia's army on Monday did not report progress in Ukraine's eastern city of Bakhmut after the Wagner mercenary group claimed it had captured the city's administration building.
"From a legal point of view, Bakhmut has been captured. The enemy is concentrated in western areas," Wagner chief Yevgeny Prigozhin said in a video posted on Telegram.
In a video accompanying the post Prigozhin could be seen holding a Russian flag, which he said his forces would plant on Bakhmut's city hall.
The Russian defense ministry, however, did not report any advances by its forces in a daily briefing on the offensive.
The fight for the industrial city of Bakhmut is the longest battle of Russia's military campaign in Ukraine.
Ukraine's army said its troops repelled Russian attacks and were still holding Bakhmut.
Prigozhin -- an ally of President Vladimir Putin -- has for months been involved in a power struggle with the defence ministry, claiming battlefield victories ahead of Russia's army and accusing the military of not sharing ammunition with his forces.
