Ukraine and Russia on Friday blamed each other after shelling hit a high-voltage power line at a Ukrainian nuclear power plant captured by Russia.

Kyiv accused Russian forces of strikes near the Zaporizhzhia power plant in the country's south, Europe's largest.

"Three strikes were recorded on the site of the plant, near one of the power blocks where the nuclear reactor is located," Energoatom, Ukraine's state-run operator of the country's nuclear power plants, said in a statement.

"There are risks of hydrogen leakage and radioactive spraying. The fire danger is high," it said, adding that initially there were no casualties.

Earlier, the Russian-installed administration of the occupied Ukrainian city of Enerhodar said Ukrainian shells struck the lines at the plant, in the country's southeast

The Interfax news agency cited the city administration as saying fire had broken out on the plant's premises, and that power necessary for the safe functioning of reactors had been cut off.

The plant was captured by Russian forces in early March in the opening stage of the war.

Energoatom said the plant – located about 200 kilometers (160 miles) northwest of the Russian-held port of Mariupol – still worked and no radioactive discharges had been detected.

Further east, both sides claimed small advances while Russian artillery bombarded towns and villages across a wide area in a now-familiar tactic.

Fighting on the ground appeared to be most intense around Pisky in Donetsk region, a fortified village held by Ukrainian troops and close to Donetsk city, which is in the hands of Russian-backed separatist forces.

The Russians also have the cities of Bakhmut and Avdiivka in their sights as they try to gain full control of the eastern Donbas area, Ukraine's industrial heartland.