Corps) under Erwin Rommel was dispatched to secure the Axis front in Africa in February 1941. Operation Colossus signalled a dramatic turn around. The Germans launched Operation Sonnenblume, which reinforced the Italians in North Africa. They then began a counter-offensive and drove the British back into Egypt. But operating overseas in Africa meant most of the supplies to Axis forces would come via the sea. This made Malta a dangerous threat to Axis logistical concerns. In response, the Oberkommando der Luftwaffe (OKL or Air Force High Command) sent Fliegerkorps X (Flying Corps Ten) to Sicily, which arrived in January 1941, to strike at naval forces in and around Malta, and RAF positions on the island, to ease the passage of supplies. The British submarines failed to interdict the German ships transporting the German forces to Libya. The damaging of the 7,889-ton German ship Duisburg was the only noteworthy attack. On 9 February 1941, three submarines missed the same convoy bringing supplies to Tripoli, the principal Italian port in Libya. The port facilities could unload six ships at a time, making the port the best facility west of Alexandria, to the east. A large part of the Axis defensive success was due to naval mines. The Italians deployed 54,000 mines around Malta to prevent it being supplied. These mines were the bane of the Royal Navy's submarines. Around 3,000 mines were laid off Tunisia's coast by Italian naval forces as well. The failure to intercept Axis shipping was evident in the figures which extended far beyond February 1941. From January–April, the Axis sent 321,259 tons to Libya and all but 18,777 tons reached port. This amounted to a 94% success rate for convoy safety running the British interdiction. Of the 73,991 men sent by sea, 71,881 (97%), arrived in Africa. On 10 December 1940, Fliegerkorps X, under the command of Hans Ferdinand Geisler, and with support of his chief of staff Major Martin Harlinghausen, was ordered to Sicily to attack Allied shipping in the Mediterranean. By the start of the first German operation, Geisler had 95 aircraft and 14,389 men in Sicily. Geisler persuaded the OKL to give him four more dive-bomber gruppen (Groups). On 10 January, he could muster 255 (179 serviceable) aircraft including 209 dive and medium bombers. By 2 January 1941, the first German units reached Trapani on Sicily's southern coast. The Luftwaffes two units were both Junkers