Ukraine said its forces north and south of Bakhmut were advancing on Monday, to entrap Russians inside the ruined city that Moscow says it captured over the weekend after Europe’s bloodiest battle for ground troops since World War II.

Russia’s proclamation on Saturday that it had finally captured the final few blocks of Bakhmut culminated a battle both sides have called a meatgrinder and gave Moscow its first chance to declare a substantial victory for more than 10 months.

But even as the Russians pushed forward inside Bakhmut, their forces on the city’s northern and southern outskirts were retreating at the war’s fastest pace for six months, giving both sides reasons to claim momentum had now shifted their way.

Moscow says capturing Bakhmut now opens the way to further advances in eastern Ukraine. Ukraine says its advance on the Russian forces’ flanks was more meaningful than its withdrawal inside the city, and Russian reinforcements sent to hold Bakhmut will weaken it elsewhere.

“Through our movement on the flanks — to the north and south — we manage to destroy the enemy,” Ukrainian deputy defence minister Hanna Maliar said on Monday in televised comments.

“By moving along the flanks and occupying certain heights there, our armed forces have made it very difficult for the enemy to stay in the city itself.”

Ukrainian forces were still advancing, particularly south of Bakhmut, Maliar said, though she said the intensity of fighting on the northern flank had subsided for now. Reuters could not independently verify the situation in either location. Maliar also said Ukraine still held a foothold inside the city itself, although independent monitors say any remaining Ukrainian presence there is unlikely to be substantial.

“Wagner Group mercenaries likely secured the western administrative borders of Bakhmut City while Ukrainian forces are continuing to prioritise counterattacks on Bakhmut’s outskirts,” the Institute for the Study of War think tank said on Monday.

The battle inside Bakhmut so far has been led by Wagner, a mercenary group whose leader Yevgeny Prigozhinhas been issuing daily messages mocking the leadershipof Russia’s regular armed forces.