Ukrainian President Volodymyr Zelensky said Monday that Russia has deployed nearly 50,000 troops to Kursk, the southern Russian region where Kyiv launched its surprise counteroffensive in the summer.

The Russian counteroffensive in western Russia’s Kursk Oblast is off to a bloody and chaotic start. After six days, Ukrainian drone operator Kriegsforscher has identified 77 destroyed Russian armored vehicles along the northwestern edge of the 250-square-mile salient Ukrainian troops occupy in Kursk.