The Russian-controlled management of the Zaporizhzhia nuclear power plant, the largest in Europe, said Thursday the Ukrainian army had shelled a critical infrastructure facility at the plant.

An explosive device was dropped near a fence where diesel fuel tanks are located, the plant reported.

"Such attacks are unacceptable," it said.

It was not immediately clear when the attack had taken place. Reuters was unable to immediately verify battlefield reports from either side.

International Atomic Energy Agency Director General Rafael Grossi has repeatedly warned of the danger of attacks on the plant.

Russia and Ukraine, at war for more than two years, have blamed each other for past shelling that has downed power lines and endangered generators.