Russia said on Friday that Ukrainian forces had attacked Russian positions along almost 100 km of the front line near Soledar, a small mining town near Bakhmut in eastern Ukraine that Moscow’s forces seized in January.

As anticipation grows of a Ukrainian counteroffensive aiming to drive Moscow’s forces out of the land they have seized in the last 15 months, deputy defence minister Hanna Maliar confirmed earlier reports that Ukraine had made some gains near Bakhmut but appeared to play down suggestions of a wider push.

The Russian defence ministry said 26 attacks involving over a thousand troops and up to 40 tanks near Soledar on Thursday had been repulsed. In one area, Russian forces had fallen back to “more favourable positions” near a reservoir northwest of Bakhmut.

Reuters was not able to verify the battlefield reports, and there was no immediate response from Kyiv, which during previous offensives has maintained strict silence about its operations while they were underway.

An attack at Soledar, just north of Bakhmut, would appear to substantiate reports by Russia’s Wagner private army that Kyiv was launching its offensive on the city’s north and south flanks, aiming to surround it. Earlier this week, a Ukrainian unit claimed to have routed a Russian brigade southwest of Bakhmut in Ukraine’s biggest advance for six months.

Wagner leader Yevgeny Prigozhin has said the flanks, guarded by regular troops, are crumbling, putting his group’s positions inside the city at risk. Russia’s defence ministry denied this.

Without giving details, Ukrainian deputy defence minister Maliar said Kyiv’s forces had advanced by about 2 km this week around Bakhmut without ceding any ground. A claim of such swift progress is rare in an attritional battle in which Russia has made incremental advances over the last 10 monthswithout being able to claim the city.

Moscow has been preparing since last autumn for an expected onslaught and built lines of anti-tank fortifications along hundreds of miles of front.

It has also begun evacuating civilians who have been living near the conflict zone in Ukraine’s partially occupied Zaporizhzhia province to areas farther from the expected advance by Kyiv’s forces.