Defense ministry in Russia said it has stopped a significant Ukrainian offensive in Donetsk, killing 250 soldiers and destroying armoured vehicles.
Video of what Russia says is the battle appears to show military vehicles coming under heavy fire in fields.
However, Kyiv has not responded, and it has not been possible to independently verify Russia’s assertion.
According to Kyiv, Ukraine will not announce the long-awaited Ukrainian counteroffensive in advance.
It is too soon to judge if this claimed onslaught marks the beginning of Kyiv’s eagerly anticipated counterpunch.
However, there has been a noticeable rise in military action as Ukraine claims to have made minor gains elsewhere on the front line.
Using six mechanized and two tank battalions, the Russian defense ministry claimed that Ukraine had started a “large-scale offensive” in the Donetsk region on Sunday.
It claimed the Ukrainians tried to break through Russian defences in what Kyiv saw as the most vulnerable part of the front line – but that it “did not achieve its tasks, it had no success”.
Moscow asserted that Ukraine had lost 16 tanks and 250 soldiers.
The footage featured masked and well-armed troops holding their fingers against their lips.
The Russian defense ministry’s assertions have not yet been confirmed. If the video of the armored trucks coming under heavy fire is real, it illustrates the fierce opposition Ukrainian forces may encounter as they attempt to recapture additional land.
And if it is not what it seems, it is still an attempt by Moscow to take control of the narrative.
There has been a significant increase in Ukrainian messaging on when and how their much-anticipated counter-offensive could take shape.
Ukraine has been planning a counter-offensive for months. But it has wanted as much time as possible to train troops and to receive military equipment from Western allies.
Officials in Kyiv have warned against public speculation over the offensive, saying it could help the enemy.
It will take Ukraine time to achieve its goal of liberating territory taken by Russia as far back as nine years ago.