Moscow on Friday reported intense fighting near southeast Ukraine settlements that had until recently been under its control, which appeared to indicate advances by Kyiv's forces.
Russian officials — including President Vladimir Putin — have repeated that Ukraine's long-expected counteroffensive was failing despite Kyiv claiming some gains.
But the Russian army said the most active fighting took place around the settlements of Rivnopil and Urozhaine, which are near a cluster of villages that Ukraine claimed to recapture over the past week.
Russia said "five attacks from units of the Ukrainian armed forces were repelled" around Rivnopil and Urozhaine.
Fighting in this area would mean Russian defense lines have fallen back a few kilometers in areas at the border between the partially occupied southern Zaporizhzhia and the eastern Donetsk region.
On Thursday the Ukrainian army said it continued to advance despite "powerful resistance" from Russian troops.
The area where the heavy fighting is taking place is still more than a dozen kilometers north of Russia's heavily fortified defense lines.
Major Ukrainian military successes in the southern Zaporizhzhia region could potentially enable Ukraine's forces to break through the land bridge that connects Russia with the Crimean peninsula it annexed from Ukraine. This would be a major reversal for Moscow.
Analysts say Ukraine is yet to launch the bulk of its forces on the battlefield and is likely still probing Russian defenses.
