Russia's Wagner mercenary group captured the eastern city in May after 10 months of fighting. Since then, the Russian army in the area has come under fierce pressure from Ukrainian forces who threaten to encircle it.

The Russian defence ministry made no comment in its daily briefing on reports that Russian forces have retreated from the village of Klishchiivka southwest of Bakhmut, which a Russian-installed official in eastern Ukraine denied.

Ukraine has said its forces have had "partial success" in the Klishchiivka area.

Russia's RIA news agency cited a Russian army source as saying that Russian forces had successfully repelled a Ukrainian attack there without retreating and were finishing off the remainder of Ukrainian troops in the area.

Reuters could not independently verify the battlefield situation.