سيدي براني
Selby Force guarded the eastern approaches to Sidi Barrani, as the rest of the WDF attacked the fortified camps further inland. On 10 December, the 4th Armoured Brigade, which had been screening the attackers from a possible Italian counter-attack from the west, advanced northwards, cut the coast road between Sidi Barrani and Buq Buq and sent armoured car patrols westwards. The 7th Armoured Brigade remained in reserve and the 7th Support Group blocked an approach from Rabia and Sofafi to the south. News of the fall of Nibeiwa reached Selby at who sent troops to block the western exists from Maktila. Difficult going and darkness slowed the move and the 1st Libyan Division escaped. Late on 9 December, O'Connor and Beresford-Pierce sent the 16th Infantry Brigade (Brigadier Cyril Lomax) from reserve to cut the roads into Sidi Barrani, two field artillery regiments supported the advance and the 7th RTR rushed to get unserviceable tanks back into action. Sidi Barrani was defended by two Italian divisions in eight strongpoints, each defended by a battalion but the defensive perimeter was too long for effective command.