ISTANBUL Russia claimed on Sunday that it struck an oil refinery in Ukraine’s central Poltava region in an overnight group strike. A statement by the Defense Ministry said high-precision air and sea-based weapons were used in targeting the refinery in the industrial city of Kremenchuk. According to the ministry, the facility supplied fuel to Kyiv's forces in the Donbas region of eastern Ukraine, where intense clashes continue. Acting Poltava Governor Volodymyr Kohut confirmed the combined