UNDISCLOSED LOCATION IN SOUTHERN UKRAINE: In a field in southern Ukraine, soldiers scrawled sardonic messages on a sleek grey attack drone that would soon be hunting Russian ships on the Black Sea — part ​of a widening Ukrainian campaign to isolate Crimea and weaken Moscow’s war effort.

Operating far behind the front line on Ukraine’s sweeping steppe, such units have hit more than 180 vessels and other sea-borne targets around the peninsula over the past three weeks, opening a new front in the war.

The attacks, first in the Sea of Azov and now expanding into the Black Sea that it opens into, are designed to raise the cost for Russia of occupying Crimea and to swing the initiative toward Kyiv in the fifth year of full-scale war in Ukraine.

“We work day and night, every day, without time off,” said battalion commander “Ray” of Magyar’s Birds, a brigade that is an important part of the effort. In line with Ukrainian military practice, he identified himself only by his call sign.

During a recent visit by Reuters, his team launched drones every couple of minutes. The unit said it struck a cargo vessel and floating crane ‌in the Black Sea ‌and a power substation in south Crimea. Reuters could not independently verify this.