Moscow says Ukraine has resumed its strikes on Russian oil refineries after a "pause" of several days. ( Reuters )
Russia has opened a terrorism case over a Ukrainian attack on an industrial facility in the Nizhny Novgorod region.
Earlier, the region's governor said an unnamed facility had sustained "significant damage" after a "massive" drone attack.
Ukrainian media reported the attack had hit the Kstovo oil refinery, calling it "one of Russia's largest".
Russian investigators have opened a criminal case on terrorism charges over a Ukrainian attack on an industrial facility in the Nizhny Novgorod region, state news agency TASS reports.
Earlier on Sunday, the region's governor said an unnamed facility had sustained "significant damage" after a "massive" drone attack.
Ukrainian media reported the attack had hit the Kstovo oil refinery, calling it "one of Russia's largest oil refineries, producing fuel and lubricants".
Regional authorities said they were taking all necessary measures to ensure fuel remained available at petrol stations. There were no casualties reported.
Meanwhile, hundreds of thousands of households in Ukraine were left without power on Sunday after Russia hit power infrastructure in four Ukrainian regions overnight, President Volodymyr Zelenskyy said on Telegram.
"The intensity of the strikes is very high, and the Russians are seeking to maximally exploit the deficit of ballistic missile interceptors," Mr Zelenskyy said.
He said Ukraine had hit the Kamensky plant in Russia's Rostov region, which he said was involved in the manufacturing of Russian missiles.
Overall, Russia's Defence Ministry said its forces had downed 235 Ukrainian drones across Russian regions overnight.
Ukraine's air force said it had shot down 371 of 433 long-range drones launched by Russia since Saturday evening.
Moscow said on Friday that Ukraine had resumed its strikes on Russian oil refineries after a "pause" of several days.
Senior Russian official Alexander Novak told a reporter from state TV that Ukraine had resumed attacks on Russian plants, hitting three oil refineries and one gas-chemical complex.
Kyiv has repeatedly struck Russian oil and gas sites in retaliation for Russian attacks on Ukrainian energy infrastructure since Moscow began its offensive there in February 2022.
US President Donald Trump had been pressuring Kyiv for weeks to stop such attacks, blaming them for the rising cost of diesel.
Russian President Vladimir Putin has previously indicated he would resume peace talks with Ukraine and the US.
A Kremlin aide said on Sunday that Mr Putin would answer the phone to Mr Zelenskyy if he called, saying Putin "has never refused talks", state media reported.
The aide added initial negotiations should include only Russia, Ukraine and the US, with other European countries excluded.
