Another photo showed rescue services tackling what appeared to be a fire, with a pall of grey smoke rising into the air.
"The 'Rashists' ('Russian fascists') knew very well where they were aiming and what they wanted: they wanted to sow panic and fear, they wanted to take as many civilians as possible," he wrote in an online post.
Reuters could not immediately verify the photos.
Ukrainian officials say Russian forces have been regrouping for a new offensive, and that Moscow plans to seize as much territory as it can in the eastern part of Ukraine known as Donbas bordering Russia.
Local authorities in some areas have been urging civilians to leave while it is still possible, and relatively safe, to do so.
Russia denies targeting civilians in a "special military operation" aimed at demilitarizing and "denazifying" Ukraine. The Kremlin's position is rejected by Ukraine and the West as a pretext for an unprovoked invasion.