The leader of the Russian paramilitary group Wagner said Sunday that his troops had taken an eastern Ukrainian village a few kilometres from the key city of Bakhmut which Moscow has been trying to capture for months.
"Today, Wagner's assault units took the town of Krasna Hora," Wagner's chief Yevgeny Prigozhin said in a statement.
AFP was unable to independently confirm the claims.
Experts have debated the strategic importance of Bakhmut, but the city has turned into a key political and symbolic prize as the battle has dragged on.
Rivalry between the paramilitary Wagner group and the Russian army have come to the surface during the fight for Bakhmut -- though the Kremlin denies any rift.
On January 11 Prigozhin claimed his fighters had taken control of the city of Soledar, a salt-mining town with a pre-war population of around 10,000 near Bakhmut.
The Russian defence ministry only said two days later that Moscow's forces were controlling the town.
"After the capture of Soledar and the mass hype saying that there were other (soldiers) besides Wagner in Soledar, of course, the guys were very frustrated," Prigozhin said Sunday.
"Within a 50 kilometres (31 miles) radius, more or less, only Wagner fighters remain, and they will take Bakhmut," he added.