MOSCOW (Reuters) -Ukraine attacked Moscow on Wednesday with at least 11 drones that were shot down by air defences in what Russian officials called one of the biggest drone strikes on the capital since the war in Ukraine began in February 2022. The war, largely a grinding artillery and drone battle across the fields, forests and villages of eastern Ukraine, escalated on Aug. 6 when Ukraine sent thousands of soldiers over the border into Russia's western Kursk region. For months, Ukraine has also fought an increasingly damaging drone war against the refineries and airfields of Russia, the world's second largest oil exporter, though major drone attacks on the Moscow region - with a population of over 21 million - have been rarer.