No further details were provided.
"In Kharkov, there were hits ... on [Ukrainian] manpower, and an ammunition depot was hit significantly," Sergey Lebedev, coordinator of the pro-Russian underground network in Nikolaev, wrote on Telegram.
Russian troops have been striking at infrastructure and critically important assets across Ukraine in response to attacks by the Ukraine military on civilian targets in Russia. Kremlin spokesman Dmitry Peskov said Russia was not targeting civilian assets.