Russian shelling hit a residential area in the southern region of Mykolayiv, wounding 12 civilians, including four children, on August 20, Ukrainian officials said.
A five-story apartment building and private homes in the town of Voznesensk were badly damaged by shelling that collapsed balconies and blew out windows, the Black Sea region's governor, Vitaliy Kim, said.
Voznesensk is about 30 kilometers from the Pivdennoukrainsk nuclear power plant, the second largest in Ukraine. There were no reports of any damage to the nuclear plant.
The state-run Energoatom, which manages all four Ukrainian nuclear energy generators, described the attack on Voznesensk as "another act of Russian nuclear terrorism."
"It is possible that this missile was aimed specifically at the Pivdennoukrainsk nuclear power plant, which the Russian military tried to seize back at the beginning of March," Energoatom said in a statement.
Russian officials did not immediately respond to the accusation.
Ukraine has called on the United Nations and other international organizations to force Russian forces to leave another nuclear power station, Zaporizhzhya which has been occupied since soon after Russia invaded Ukraine on February 24.
The international community have expressed deep concern over the risk of disaster at the Zaporizhzhya plant amid reports of fighting in its vicinity in recent days. Both Ukraine and Russia have accused each other of shelling the plant.