B集團軍
On 24 May Army Group B launched an attack on the Belgian forces stationed along the River Lys east of Menin. This achieved rapid success and as a result Army Group B conceived the idea of changing the direction of attack from northwest to west, in order to cut off the British and French forces in the pocket from the coast. Orders to that effect were issued by German 6th Army, part of Army Group B, at 23.30 on 24 May.