Lütjens remained unaware that the British were tracking him until 23 May, when his ships encountered heavy cruisers and , amidst the Greenland ice pack. Lütjens received the identity of the first ship as the latter vessel. He gave the code JOTDORA: permission to fire. Although shots were fired, no serious damage resulted to either side, and the outgunned British cruisers quickly withdrew, though they remained within radar range and continued to shadow the German ships. The shock from the firing of Bismarcks heavy guns disabled her search radar, so Lütjens ordered Prinz Eugen to take the lead. As they passed each other Bismarcks electric push-button wheel jammed and it veered toward the German cruiser. The quick thinking of Brinkmann avoided a collision. During a raining squall Lütjens attempted a 180-degree turn to surprise his attackers, but the British radar detected the manoeuvre and withdrew. Lütjens could not shake his pursuers. He believed they possessed a new type of radar as yet unknown to the Germans.
