Yevgeny Prigozhin, founder of Russia's Wagner Group, said on Sunday that the mercenary force had taken the village of Krasna Hora on the northern edge of the embattled Ukrainian city of Bakhmut.
Bakhmut, a city in the eastern Donetsk region, has been the scene of brutal warfare for months. Kyiv's top military commander, Valeriy Zaluzhnyi, said on Saturday that Ukraine continues to hold Bakhmut, trying to "stabilise" the frontline around it.
In an audio message published by his press service on the messaging app Telegram, Prigozhin said: "Today the settlement of Krasna Hora was taken by the assault troops of the Wagner private military company".
Prigozhin also published a short video, apparently showing Wagner fighters at the entrance sign to Krasna Hora, which had a pre-war population of 600.
Reuters could not independently verify that the village had been taken.
The Wagner Group, a once secretive mercenary force that fought for Moscow's allies in Africa and the Middle East, has for months spearheaded the assault on Bakhmut, making small but steady gains.
In his audio message, Prigozhin also said that only Wagner troops are fighting within "a radius of give or take fifty kilometres" around Bakhmut, and should the city be taken, it would be by Wagner units. He added that Wagner is not fighting in other areas of the front further north or south.
Prigozhin has previously engaged in public feuds with Russia's Defence Ministry, which he has accused of taking credit for Wagner successes.
Prigozhin said in an interview published on Friday that his forces must capture Bakhmut to proceed with their campaign but faced fierce resistance from Ukrainian defenders.
He also said that it could take two years for Moscow to control the whole of two eastern Ukrainian regions whose capture it has stated as a key goal of the war.
(Reporting by ReutersEditing by Susan Fenton and Frances Kerry)