Russia Begins Fresh Assault in Eastern UkraineKYIV, UKRAINE — As Russia began an assault Saturday on two key cities in eastern Ukraine, Kyiv and Moscow blamed each other for a strike on Ukraine's Zaporizhzhia power station, Europe's largest nuclear power plant. Russian troops have occupied the Zaporizhzhia nuclear plant, located in southern Ukraine, since March. Ukraine has accused Russia of storing heavy weapons there, while Russia accused Ukraine of targeting the plant. "Three strikes were recorded on the site of the plant, near one of the power blocks where the nuclear reactor is located," according to a statement Friday from the operator of Ukraine's state-run nuclear power plant. "There are risks of hydrogen leakage and radioactive spraying. The fire danger is high." However, plant operator Energoatom also said there were no signs of damage that would cause a radioactive leak. The European Union's top diplomat demanded that Russia give the U.N.'s nuclear watchdog, the International Atomic Energy Agency (IAEA), open access to the plant. "This is a serious and irresponsible breach of nuclear safety rules and another example of Russia's disregard for international norms," Josep Borrell said on Twitter. Ukraine has rejected IAEA efforts to visit the plant in the last few weeks, saying such a visit would legitimize Russia's occupation of the plant in the eyes of the international community. New attacks On Saturday, Russian forces began an assault on the strategic cities of Bakhmut and Avdiivka in the Donetsk region in eastern Ukraine, according to Ukrainian military and local officials. Bakhmut and Avdiivka are prime targets for Russia; analysts say Moscow must take Bakhmut in order to advance on the key regional hubs of Sloviansk and Kramatorsk. Russia last attacked Sloviansk on July 30, but Ukrainian forces are fortifying their positions around the strategic eastern city ahead of anticipated fresh Russian attacks. Sloviansk is strategic in Moscow's ambitions to seize the entire Donetsk region, a largely Russian-speaking area in eastern Ukraine. Russian forces and pro-Moscow groups control about 60% of the province. Russia-Turkey cooperation Meanwhile, Turkish President Recep Tayyip Erdogan confirmed Saturday that Turkey will pay for some Russian natural gas in rubles, the official currency of Russia. The move is seen as a way to help insulate Russia from Western sanctions. Payments in rubles would be protected from sanctions. The United States is spearheading international efforts to impose economic sanctions on Russia for its February invasion of Ukraine. Turkey is a NATO member but has refused to take part in sanctions, in part because Turkey is heavily dependent on Russian energy. Erdogan also said Saturday that he offered to host talks in Turkey between Russia and Ukraine. He said he made the offer when he met with Russian President Vladimir Putin on Friday in Sochi, the Kyiv Independent reported. Some information in this report came from the Associated Press, Reuters and Agence France-Presse.