Russian missiles hit a Ukrainian army command post where generals and other senior officers had gathered for a meeting.
Defence spokesman Igor Konashenkov said 50 senior officers were killed in the attack in a town near the town of Krivi Rih, more than 350 kilometres southeast of Kyiv. There are no reports from the Ukrainian side about the missile strikes.
Among the dead are generals who led the battle in the Mykolayiv and Zaporizhzhya regions.
Konashenkov also reported, as usual, of the destruction of much military equipment in several places in Ukraine, which had been recently made available by allies, including armoured vehicles and missile launch systems.