(Reuters) - Ukrainian forces have counterattacked in the contested city of Sievierodonetsk in eastern Ukraine, Britain's defence ministry said on Sunday.

       This move will likely blunt the operational momentum Russian forces previously gained through concentrating combat units and firepower, the ministry said in a tweet.

       "The use of proxy infantry forces for urban clearance operations is a Russian tactic previously observed in Syria, where Russia employed V Corps of the Syrian Army to assault urban areas," it said, adding that the approach likely indicates a desire to limit casualties suffered by regular Russian forces.

       (Reporting by Jahnavi Nidumolu in Bengaluru; Editing by William Mallard)