Britain's Defense Ministry said Russia continues to besiege a number of major Ukrainian cities including Kharkiv, Chernihiv and Mariupol.<br />''<br />''A daily update says Russian forces are reluctant to engage in large-scale urban infantry operations, rather preferring to rely on the indiscriminate use of air and artillery bombardments in an attempt to demoralize defending forces.<br />''<br />''<br />''<br />