British naval force destroyed supply ships at Bardia according to the War Cabinet Weekly Résumé No. 45 of the Naval, Military and Air Situation 4-12 July 1940

An item reported that a British force consisting of cruisers and destroyed on 6 July with success ships in the Bardia harbour part of the Libya-Egptian frontier sinking two military supply ships. Enemy aircraft attacked without success the British ships.

Source

National Archive UK. CAB-66-9-42.