LONDON -- Millions of Ukrainians have been plunged into frequent darkness and cold as Russian drones and missiles wage a systematic long-range campaign against the country's energy grid for the fourth consecutive winter. Even at the offices of Ukraine's mammoth state-owned Naftogaz oil and gas conglomerate in Kyiv, emergency generators have been keeping the lights on. "What I can see from my window -- there is an absolutely dark city with only some lights," CEO Sergii Koretskyi told ABC News during a video interview. "I'm sure people recognize this winter as the most difficult since the full-scale invasion started. We can see power cuts from four up to 10 hours a day." Russia's nightly bombardments have increasingly targeted energy infrastructure in recent months, Ukrainian officials say,

See Full Page