Northern front, 1940 British Somaliland 1940 On 3 August 1940, the Italians invaded with two colonial brigades, four cavalry squadrons, tanks and L3/35 tankettes, several armoured cars, batteries, pack artillery and air support. The British had a garrison of two companies of the Sudan Defence Force, two motor machine-gun companies and a mounted infantry company. Kassala was bombed and then attacked, the British retiring slowly. On 4 August, the Italians advanced with a western column towards Zeila, a central column (Lieutenant-General Carlo De Simone) towards Hargeisa and an eastern column towards Odweina in the south. The SCC skirmished with the advancing Italians as the main British force slowly retired. On 5 August, the towns of Zeila and Hargeisa were captured, cutting off the British from French Somaliland. Odweina fell the following day and the Italian central and eastern columns joined. On 11 August, Major-General Alfred Reade Godwin-Austen was diverted to Berbera, en route to Kenya to take command as reinforcements increased the British garrison to five battalions. (From 5 to 19 August, RAF squadrons based at Aden flew 184 sorties, dropped of bombs, lost seven aircraft destroyed and ten damaged.) Battle of Tug Argan On 11 August, the Italians began the Battle of Tug Argan (, a dry, sandy riverbed), where the road from Hargeisa crosses the Assa hills and by 14 August, the British were at risk of defeat in detail by the larger Italian force and its greater quantity of artillery. Close to being cut off and with only one battalion left in reserve, Godwin-Austen contacted Henry Maitland Wilson the General Officer Commanding-in-Chief the British Troops in Egypt in Cairo (Wavell was in London) and received permission to withdraw from the colony. The 2nd Battalion, Black Watch, supported by two companies of the 2nd King's African Rifles and parties of the 1st/2nd Punjab Regiment covered the retreat of the British contingent to Berbera. By on 18 August, most of the contingent had been evacuated to Aden but and the HQ stayed behind until morning before sailing and the Italians entered Berbera on the evening of 19 August. In the final four days, the RAF flew twelve reconnaissance and sorties, with on Italian transport and troop columns; sorties were flown over Berbera. The British suffered casualties of and the Italians suffered fuel and ammunition expenditure and wear and tear on vehicles was difficult to remedy, which forced the Italians