Ukraine unleashed more than a hundred drones smuggled deep into Russia in what it called its most damaging attack yet.

Russia conducted its second-largest missile and drone attack on Ukraine since the start of its invasion in 2022, according to the Institute for the Study of War ( ISW) whose graph illustrate the response to Kyiv's drone barrage on Russian military airfields.

Previous attacks by Ukraine inside Russia have triggered retaliatory strikes and increasingly threatening rhetoric from the Kremlin. But this latest operation is one of the biggest and most significant.