Ukraine has denied claims that Russia killed 600 soldiers in an attack.
The Kremlin had claimed, without providing any evidence, that a "mass missile strike" in the city of Kramatorsk had left hundreds of troops dead.
Moscow said that the attack was in retaliation for an assault on a Russian base that killed dozens of Russian soldiers on New Year's Day (01.01.23).
However, the claims have been dismissed as "propaganda" by Kyiv.
Serhiy Cherevaty, a spokesman for the Ukrainian army, told the BBC: "This is another piece of Russian propaganda."
Russia is yet to offer any proof of its claim about deaths in Kramatorsk but the BBC has confirmed that strikes took place on two sites about a mile apart in the city.
The strikes occurred near two school buildings, vocational schools number 28 and 47, which match the dormitory numbers that have been provided by Moscow. The Kremlin claims that the buildings were housing Ukrainian military personnel.
However, there is no visual evidence to show that the buildings have been badly hit or that there have been deaths on the scale of that claimed by Russia.