water per day. 1940 Frontier skirmishes On 11 June 1940, hostilities commenced. British troops were ordered to dominate the frontier and isolate Giarabub. They crossed into Libya that night, exchanged fire with Italian troops at Sidi Omar and discovered that some Italians were unaware that war had been declared. On 14 June, the British captured Fort Capuzzo and Fort Maddalena, taking 220 prisoners. Two days later, the British raided a convoy on the Tobruk–Bardia road, killed 21 Italian soldiers and took 88 prisoners, including (Brigadier General) Romolo Lastrucci, the 10th Army Chief Engineer. At an engagement near the frontier wire at Nezuet Ghirba, a mixed force of British tanks, artillery and motorised infantry defeated an Italian force of 17 light tanks, four guns and 400 infantry. The British patrolled the frontier area as far west as Tobruk, establishing dominance over the 10th Army. On 5 August, thirty Italian tanks engaged the 8th Hussars in an inconclusive action and Wavell concluded that vehicle wear made it impractical to continue operations when an Italian offensive loomed. Sand wore out equipment quickly, shortening the track life of tanks. Spare parts ran out and only half the tank strength could be kept operational. A lull fell from August to early September as Operation Hats, a naval operation, reinforced the Mediterranean Fleet and helped to bring an army convoy of tanks and crews via the Cape. The British claimed to have inflicted 3,500 casualties with a loss of 150 men between 11 June and 9 September. Further afield, both sides established scouting groups, the Long Range Desert Group (LRDG) and Auto-Saharan Company () which ranged the desert, raided and observed enemy dispositions. E Benito Mussolini had no plans to invade Egypt, intending to remain on the defensive in Libya if war came. After the fall of France in 1940, the 5th Army could send reinforcements east and on 7 August, Mussolini ordered an invasion to occupy Egypt and establish a land connexion with Italian East Africa. In August a lull fell on the frontier. Most British armoured units had withdrawn to Mersa Matruh, in order to conserve their ability to defend the port. The 7th Support Group took over and established observation posts from Sollum to Fort Maddalena, ready to delay an Italian offensive and the Hussars reconnoitred further into Libya. The Libyan divisions lacked the transport necessary to operate with the Maletti Group, which