Ukraine struck the Moscow region on Tuesday in its biggest drone attack so far on the Russian capital, killing at least one woman, wrecking dozens of homes and forcing around 50 flights to be diverted from airports around Moscow.

Russia, the world’s biggest nuclear power, said it destroyed at least 20 Ukrainian attack drones as they swarmed over the Moscow region, which has a population of more than 21 million, and 124 more over eight other regions.

At least one person was killed near Moscow, Russian authorities said. Three of Moscow’s four airports were closed for more than six hours and almost 50 flights were diverted.