The head of Russia’s Wagner paramilitary group said his mercenaries had captured Bakhmut in eastern Ukraine on Saturday, a claim the Ukrainian military denied even as its soldiers have been forced into an ever-shrinking patch of land inside the ruined city.

Senior Ukrainian military officials acknowledged that the situation inside the city was "critical,” with soldiers facing an unrelenting barrage of artillery fire and powerful aerial bombardments. Nevertheless, they said, the Ukrainian forces were still engaged in combat operations.

The Russian Ministry of Defense and the Kremlin released a statement confirming the city had been "liberated,” hours after the declaration by the Wagner chief, Yevgeny Prigozhin, that the fight for the city was over. After nearly a year of fighting, Bakhmut has taken on an outsize importance: a symbol of Ukrainian defiance and of Russian leaders’ determination to blast their way to a small victory in a little-known corner of eastern Ukraine.