The head of the U.N. nuclear watchdog has warned that whoever fired artillery at Ukraine's Zaporizhzhia nuclear power plant was "playing with fire" as his team prepared to inspect it on Monday for damage from the weekend strikes.

The attacks on Europe's biggest nuclear power plant in the south of Ukraine came as battles raged in the east, where Russian forces pounded Ukrainian positions along the front line Ukrainian President Volodymyr Zelenskyy said.

The shelling of the Zaporizhzhia nuclear power station follows setbacks for Russian forces in the Kherson region in the south and a Russian response that has included a barrage of missile strikes across the country, many on power facilities.