 A series of air raids were mounted against Bardia in December , in the hope of persuading the garrison to withdraw . Once it became clear that the Italians intended to stand and fight , bombing priorities shifted to the Italian airbases around Tobruk , Derna and Benina . Air raids on Bardia resumed in the lead @-@ up to the ground assault , with 100 bombing sorties flown against Bardia between 31 December 1940 and 2 January 1941 , climaxing with a particularly heavy raid by Vickers Wellington bombers of No. 70 Squadron RAF and Bristol Bombay bombers of No. 216 Squadron RAF on the night of 2 / 3 January 1941 . Lysanders of No. 208 Squadron RAF directed the artillery fire . Fighters from No. 33 Squadron RAF , No. 73 Squadron RAF and No. 274 Squadron RAF patrolled between Bardia and Tobruk . 
