On 25 April 1941 the German Kampfgruppe Herff was supposed to take Halfaya Pass, on the Lybian-Egyption border, with air support.
The German aircraft (probably Bf 110s of ZG 26) attacked the concentration area of the German forces rather than Allied positions, and the Kampfgruppe lost 7 dead and 10 wounded only in this "friendly" air attack.
See
https://rommelsriposte.com/2016/08/2...25-april-1941/