2/48th Australian Battalion, three infantry tanks and a troop of 25-pounders, raided a hillock held by the Fabris Detachment south-west of Ras el Medauar; the raiders destroyed two guns and took At the same time a company of the 2/23rd Battalion advanced across the Derna road and in a costly attack, took about from the 27th Infantry Division "Brescia", which led the Germans to hurry on the 15th Panzer Division from Tripoli. Air and sea war The defeat of the Axis attacks in April greatly improved the situation in Tobruk but Fliegerkorps X had sent to Libya from Sicily in February, which flew frequent dive-bomber sorties by day and medium-bomber raids by day and night on the docks, buildings, anti-aircraft sites, artillery positions and the airfields. Westland Lysander aircraft and all but the most essential ground crew of 6 and 73 Squadron were withdrawn to Egypt. At least ten Hawker Hurricane fighters were based at the port during the day and on 19 April, Hurricanes of 73 and 274 Squadrons, intercepted a Ju 87 raid escorted by fighters. After another two days, 73 Squadron was down to five operational aircraft with very tired pilots. By 23 April, three more Hurricanes had been shot down, a further two were damaged and on 25 April the squadron was withdrawn. The fighters of 274 Squadron stayed at Gerawla and 6 Squadron remained at Tobruk to fly tactical reconnaissance sorties. Fighter cover could only be maintained at intervals by the last in the desert; Axis airfields at Gazala, Derna and Benina, were bombed at dusk and night to limit Axis air attacks on Tobruk. The Desert Air Force [so-named from October 1941] flew long-range missions to attack German armour massing near Tobruk in the early stages of the siege. On 12 April, for example, 45 and 55 Squadron Bristol Blenheim bombers, operating from airfields in Egypt, attacked German tank formations near the port. The attack succeeded in breaking up the German advance. Air Commodore Raymond Collishaw, commanding 204 Group RAF (renamed the Desert Air Force), wrote to Air Marshal Arthur Tedder on 24 April. In his view the situation in the air had rapidly deteriorated. The arrival of two German fighter wings (Jagdgeschwader 27 and Zerstörergeschwader 26) near Tobruk allowed the enemy formations to arrive at great height within ten minutes of an air raid warning, leaving British fighters at lower altitude and a