Germany's Leopard tanks were spotted in the area near the city of Bakhmut, the Donetsk region, Yan Gagin, advisor to the Acting Head of the Donetsk People's Republic said, the Rossiya TV channel reports.
Slushy soil in the region makes it difficult for heavy vehicles like the Leopard to move, Gagin said.
In late January, a number of countries announced the supplies of several models of tanks to Ukraine such as Leopard (Germany), Challenger (the UK) and Abrams (the USA).
On February 26, Yevgeny Prigozhin, the founder of PMC Wagner, said that there were no fights with the Leopards so far.
"We have information that the Leopards arrive at Chasov Yar [near Bakhmut], but we have not encountered them on the battlefield yet," Prigozhin said.