More than six weeks after the Russian siege began, Ukrainian troops are continuing to fight the vastly superior Russian forces in ferocious battles amid the ruins of what once was a bustling city on the Sea of Azov.

The mayor says an estimated 120,000 people remain in the city, out of Mariupol’s prewar population of about 450,000.

The Ukrainians’ fight has scuttled Moscow’s designs, tying up significant Russian forces and delaying a planned offensive in eastern Ukraine’s industrial heartland, Donbas. The Kremlin hopes an attack in the east could reverse the battlefield fortunes for Russia after a humiliating failure to quickly storm the capital, Kyiv.